The Renewable Fuel Standard (RFS):
An Overview
Updated August 10, 2022
Congressional Research Service
https://crsreports.congress.gov
R43325

The Renewable Fuel Standard (RFS): An Overview

Summary
The Renewable Fuel Standard (RFS) requires U.S. transportation fuel to contain a minimum
volume of renewable fuel each year. The RFS—established by the Energy Policy Act of 2005
(P.L. 109-58; EPAct05) and expanded in 2007 by the Energy Independence and Security Act (P.L.
110-140; EISA)—began with requiring 4 bil ion gal ons of renewable fuel in 2006 and was
scheduled to ascend to 36 bil ion gal ons in 2022. The Environmental Protection Agency (EPA)
has statutory authority to determine the annual volume requirements after 2022.
The total renewable fuel statutory annual target consists of both conventional biofuel and
advanced biofuel. Starting in 2014, the total renewable fuel statutory target has not been met. For
the last nine years (i.e., the latter half) of the program’s statutory annual requirements, EPA set
the total renewable fuel volume below the statutory amount—using its waiver authorities—
mainly due to underproduction of advanced biofuels.
EPA administers the RFS and is responsible for several related tasks. For instance, using the
statutory criteria EPA evaluates which renewable fuels are eligible for the RFS program. Also,
EPA establishes the amount of renewable fuel that refiners and importers must account for in the
coming year based on the statutory targets, fuel supply, and other conditions, and the EPA
Administrator can exercise waiver authorities to reduce volumes if necessary. Further, the statute
requires that the EPA Administrator “reset” the RFS—modifying volumes required for future
years—if certain conditions are met. EPA also monitors compliance for the RFS using a system of
tradable credits referred to as renewable identification numbers (RINs).
Congress has expressed ongoing interest in various facets of the RFS, including smal refinery
exemptions, RFS compliance, EPA approval of fuel pathways (e.g., renewable electricity), how
EPA could determine post-2022 requirements, and how the program performs overal (e.g.,
environmental effects), among other things. For years, some in Congress have debated various
aspects of the RFS, including program management, transparency, and certainty. Further, there
have been repeated efforts by some Members to either amend or repeal the RFS, while other
Members have acted to maintain the status quo.
In July 2022, EPA published the final rule for the RFS volume requirements for 2020, 2021, and
2022 that contains a number of actions. For instance, EPA reduced the previously finalized
volume requirements for 2020 (for al fuel categories except biomass-based diesel) and set the
2021 and 2022 total renewable fuel volume requirements below the statutory targets. EPA reports
that it established the “revised volumes and standards for 2020 based on the actual volumes of
renewable fuel and transportation fuel used in the U.S. in 2020” and that “significant and
unanticipated events” (e.g., the COVID-19 pandemic) affected the fuels markets in 2020. The
final rule adds a supplemental volume of 250 mil ion gal ons of total renewable fuel for 2022 to
partial y address a court decision. The final rule contains other actions including the treatment of
confidential business information (CBI).
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Introduction
Established by Congress as an amendment to the Clean Air Act, the Renewable Fuel Standard
(RFS) mandates that U.S. transportation fuels contain a minimum volume of renewable fuel.1 The
mandated minimum volume increases annual y and general y has been met using both
conventional biofuel (e.g., corn starch ethanol) and advanced biofuel (e.g., cel ulosic ethanol).2
For a renewable fuel to be applied toward the mandate, it must be used for certain purposes (i.e.,
fuel used in on-road motor vehicles, jet fuel, or heating oil) and meet certain environmental and
biomass feedstock criteria. The Environmental Protection Agency (EPA) administers the program.
The statute outlines annual volume requirements—listed in tables—for four fuel categories: total
renewable fuel, total advanced biofuel, cel ulosic biofuel, and biomass-based diesel. The total
renewable fuel statutory volume required for any given year equates to the sum of conventional
biofuel (which is unspecified in statute) and advanced biofuel (which is specified in statute).3
Both cel ulosic biofuel and biomass-based diesel are subcategories of advanced biofuel (both of
which are specified in statute). There is also a third advanced biofuel category—other advanced
biofuels (which is unspecified in statute).4
The statutory volume requirements for both total renewable fuel and total advanced biofuel for
the RFS have not been met since 2013. The EPA Administrator has the authority to waive the
statutory RFS requirements, in whole or in part, if certain conditions outlined in statute occur.5
EPA has used this waiver authority multiple times to reduce the volumes obligated parties must
blend into transportation fuel. For instance, the 2022 targets set by EPA for total renewable fuel
and for total advanced biofuel were approximately 57% and 27% of the statutory targets,
respectively.6 A variety of factors, such as infrastructure limitations, technological development,
and limited federal assistance, have contributed to chal enges in meeting the total volume
requirement established by Congress. These chal enges have also included a lack of cel ulosic
biofuel production and the amount of time it takes EPA to approve fuel pathways.7 Oil prices,
consumer demand for transportation fuel, and circumstances related to the COVID-19 pandemic
from the last few years may also contribute to the chal enges in meeting the more recent total
statutory volume requirements.
Two fuel categories consistently have met their statutory targets for either the entire term of the
program thus far, or most of the entire term: conventional biofuel (which has an implied target)

1 42 U.S.C. §7545(o). T he term renewable fuel is defined in statute as “fuel that is produced from renewable biomass
and that is used to replace or reduce the quantity of fossil fuel present in a transportation fuel.” 42 U.S.C.
§7545(o)(1)(J).
2 T he U.S. Energy Information Administration (EIA) defines biofuels as “liquid fuels and blending components
produced from biomass feedstocks, used primarily for transportation.” U.S. Energy Information Administration,
Glossary—Biofuels, 2022.
3 Conventional biofuel equates to the difference between the total renewable fuel category and the advanced biofuel
category.
4 Other advanced biofuel is computed by subtracting both the cellulosic biofuel category and the biomass-based diesel
category from the total advanced biofuel category.
5 For more information, see CRS Report R44045, The Renewable Fuel Standard (RFS): Waiver Authority and
Modification of Volum es, by Kelsi Bracmort .
6 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register, July 1, 2022.
7 For an explanation and discussion of fuel pathways, see the “ Administering Agency” section of this report.
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The Renewable Fuel Standard (RFS): An Overview

and biomass-based diesel (which has an explicit target).8 Also, since 2014, two advanced biofuel
pathways—renewable compressed natural gas and renewable liquefied natural gas—have
constituted the majority of the cel ulosic biofuel volume requirements as finalized by EPA.9
A multitude of factors affect the conditions under which the RFS operates—some external to RFS
policy and some internal. The impact of these factors can be chal enging to quantify. For
example, it is not clear how implementation of the RFS wil adapt to changes in gasoline
consumption in response to fluctuating crude oil and gasoline prices, rising feedstock prices, and
a global event like the COVID-19 pandemic.10 It is not clear how agricultural trade issues impact
biofuel policies or the commodities used to produce biofuel.11 It is also uncertain how the
program wil fare post-2022 given that the EPA Administrator has the discretion to determine the
volume amounts for al fuel categories starting in 2023.12
Chal enges to implementing the RFS have led to scrutiny of the program in Congress and to
litigation about EPA’s regulations.13 Largely due to concerns about the implementation and
feasibility of the RFS, some Members of Congress have expressed their perspectives on EPA’s
rulemakings as wel as EPA’s implementation of the program.14 They also have questioned
whether to amend or repeal the RFS or whether to maintain the status quo.15 This report provides
an overview of the RFS, including some of the widely discussed policy issues related to it.16

8 U.S. Environmental Protection Agency, Public Data for the Renewable Fuel Standard Data, July 7, 2022.
9 Ibid. EPA defines renewable compressed natural gas as biogas or biogas-derived pipeline quality gas that is
compressed for use as transportation fuel and meets the definition of renewable fuel. EPA defines renewable liquefied
natural gas as biogas or biogas-derived pipeline quality gas that goes through the process of liquefaction in which it is
cooled below its boiling point, and which meets the definition of renewable fuel. See 40 C.F.R. §80.1401.
10 For more information on prices and energy assessments, see U.S. Energy Information Administration, Gasoline and
Diesel Fuel Update, gasoline release date: July 5, 2022; U.S. Energy Information Administration, Petroleum and Other
Liquids: Spot Prices, release date: July 7, 2022; U.S. Energy Information Administration, This Week in Petroleum ,
release date: July 7, 2022; U.S. Energy Information Administration, Annual Energy Outlook 2022, March 3, 2022; and
T able 3 in CRS Report R47051, U.S. Farm Incom e Outlook: 2021 Forecast, by Stephanie Rosch.
11 For more information on agricultural trade issues, see CRS Report R46653, Major Agricultural Trade Issues in the
117th Congress, coordinated by Anita Regmi.
12 T he Office of Management and Budget reports that a proposed rule for the RFS volume requirements for 2023 and
beyond will be released in September 2022. Office of Management and Budget, Office of Information and Regulatory
Affairs, Volum e Requirem ents for 2023 and Beyond under the Renewable Fuel Standard Program , 2060-AV14, June
21, 2022.
13 Since 2010, there have been numerous congressional hearings about the RFS. Additionally, there have been multiple
legal challenges regarding EPA’s administration of the RFS. In some cases, courts have found again st EPA’s rules for
various reasons; in others, courts have affirmed EPA’s authority.
14 See, for example, Sen. T om Carper, “Carper, Coons, Blunt Rochester Statement on EPA’s Renewable Fuel Standard
Announcement,” press release, June 3, 2022; Sen. T ammy Duck worth, “ Duckworth Applauds Biden Administration for
Getting the Renewable Fuel Standard Back on T rack with Newly Released Ethanol Blending Mandates, ” press release,
June 3, 2022; and Sen. Bill Hagerty, “ Hagerty, Capito, Wicker Seek GAO Opinion Regarding Wh ether EPA Denial of
Small Refinery Exemptions Requires Congressional Review,” press release, June 13, 2022.
15 Legislation has been introduced in the 117th Congress that would repeal, amend, or further support the RFS (see, for
example, H.R. 5701, S. 2385, H.R. 5376). For a brief discussion about potential legislative reform for the RFS, see
CRS In Focus IF10842, The Renewable Fuel Standard: Is Legislative Reform Needed? , by Kelsi Bracmort .
16 For additional discussion, see CRS Report R40155, Renewable Fuel Standard (RFS): Overview and Issues, by Kelsi
Bracmort .
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The Renewable Fuel Standard (RFS): An Overview

The Statute
The RFS was established by the Energy Policy Act of 2005 (P.L. 109-58; EPAct05).17 It was
expanded in 2007 by the Energy Independence and Security Act (P.L. 110-140; EISA) (see the
text box in this section for a discussion of the differences between the 2005 RFS and the 2007
RFS). The RFS mandate requires that transportation fuels sold or introduced into commerce in
the United States contain an increasing volume of a predetermined suite of renewable fuels. The
statute required 4.0 bil ion gal ons of renewable fuel in 2006, ascending to 36.0 bil ion gal ons
required in 2022, with EPA determining the volume amounts after 2022 in future rulemakings.
The statute centers on four renewable fuel categories—total renewable fuel, advanced biofuel,
cel ulosic biofuel, and biomass-based diesel—each with its own target volume.18 A key part of the
statutory definition of each fuel category is whether the fuel achieves certain greenhouse gas
(GHG) reductions relative to gasoline and diesel fuel. Each fuel is assigned a lifecycle GHG
emission threshold (in proportion to baseline lifecycle GHG emissions for gasoline and diesel).19
The total renewable fuel requirement under the RFS is met with the combination of fuels from
two renewable fuel categories: conventional biofuel and advanced biofuel. The requirement for
advanced biofuel, in general, can be met with the combination of three types of advanced biofuel:
cel ulosic biofuel, biomass-based diesel, and other advanced biofuels. To date, the total annual
volumes required have been met mostly with conventional biofuel (e.g., corn starch ethanol).
Beginning in 2015, the mandate implicitly capped the conventional biofuel volume amounts
while increasing the requirement for advanced biofuels.20 For instance, the statutory RFS total
advanced biofuel requirement increases over time from approximately 7% of the total renewable
fuel requirement in 2010 to 58% of the total renewable fuel target in 2022.21

17 More specifically, Section 1501 (Renewable Content of Gasoline) of EPAct05 amended Section 211 of the Clean Air
Act (CAA) by adding a Renewable Fuel Program. Section 1501 directed the EPA Administrator to ensure that gasoline
sold or introduced into commerce in the United States contained a minimum volume of renewable fuel. T his “original”
2005 RFS required 4.0 billion gallons of renewable fuel for 2006, ascending to 7.5 billion gallons by 2012. T he amount
of renewable fuel was prescribed in EPAct05 for the years 2006 through 201 2. Beginning in 2013, the annual volume
of renewable fuel was to be determined by the EPA Administrator and the Secretaries of Agriculture and Energy.
Additionally, the RFS established in EPAct05 would have required that at least 250 million gallons of the renewable
fuel be derived from cellulosic biomass starting in 2013.
18 T he statute defines the four renewable fuels. 42 U.S.C. §7545 (o)(1). Conventional biofuel is corn starch ethanol.
Advanced biofuel is renewable fuel, other than corn starch ethanol, with lifecycle greenhouse gas emissions of at least
50% less than lifecycle greenhouse gas emissions from its gasoline or diesel counterpart. Cellulosic biofuel is
renewable fuel derived from cellulose, hemicellulose, or lignin that is derived from renewable biomass, with lifecycle
greenhouse gas emissions of at least 60% less than lifecycle greenhouse gas emissions from its gasoline or diesel
counterpart. Biom ass-based diesel is biodiesel or other renewable diesel with lifecycle greenhouse gas emissions of at
least 50% less than lifecycle greenhouse gas emissions from its diesel counter part. Additionally, biofuel from new
facilities—those built after enactment of the 2007 law—must achieve at least a 20% GHG reduction to qualify as a
conventional renewable fuel. New facilities are facilities that commence construction after December 19, 2 007. 42
U.S.C. §7545 (o)(2)(A)(i).
19 For more discussion, see CRS Report R40460, Calculation of Lifecycle Greenhouse Gas Emissions for the
Renewable Fuel Standard (RFS), by Brent D. Yacobucci and Kelsi Bracmort .
20 Starting in 2015, the statute caps conventional biofuel at 15 billion gallons. From 2015 onward, the increase in the
total renewable fuel statutory target stems from the increase in the advanced biofuel statutory target.
21 Calculations include the annual mandate required by statute in 2007 and do not take into account EPA’s revision of
the biofuel mandates for 2010 through 2018.
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The Renewable Fuel Standard (RFS): An Overview

Differences Between the 2005 (“RFS 1”) and the 2007 (“RFS 2”) Laws
There are at least five major changes in the RFS as expanded in 2007 by EISA:

larger annual volume targets specified in statute for an extended period of time (i.e., through 2022),

the establishment of separate requirements for different classes of biofuels (e.g., cel ulosic, advanced),

the addition of greenhouse gas accounting requirements,

a different renewable biomass definition (as explained below), and

an expansion of EPA’s waiver authority to lower RFS volumes.
The renewable biomass definition for the RFS under EISA does not make the majority of woody biomass on
federal lands available for use as a renewable feedstock. Further, the 2007 RFS waiver authority directs the EPA
Administrator to set the annual standard for cel ulosic biofuels under the RFS for the fol owing year by November
30 of each year, and to lower the cel ulosic biofuel standard if projected U.S. production is less than the volume in
the statute. The 2007 RFS waiver authority also al ows the EPA Administrator to reduce the renewable fuel and
advanced biofuel requirements of the standard, if the cel ulosic biofuel requiremen t is lowered.
Statutory Compliance
EPA regulates compliance with the RFS using a tradable credit system.22 Obligated parties
(general y, refiners and importers) submit credits—cal ed renewable identification numbers
(RINs)—to EPA for each gal on in their annual obligation.23 (Thus, general y, each gal on of fuel
produced to meet the obligation generates its own unique RIN.24) In short, the annual obligation
for an individual refiner or importer, referred to as the renewable volume obligation (RVO), is the
obligated party’s total gasoline and diesel sales multiplied by the annual renewable fuel
percentage standards announced by EPA.25 The RVO is used by an obligated party to determine
how many RINs they are to submit to EPA at the end of a given year to be in compliance with the
mandate.
In general, the RIN lifecycle can be described in three steps:
1. a RIN is attached to a gal on of qualifying renewable fuel once that fuel is
produced,
2. the RIN is separated once the renewable fuel is blended with gasoline or diesel
fuel or used unblended, and

22 42 U.S.C. §7545(o)(5).
23 EPA defines an obligated party as any refiner that produces gasoline or diesel fuel within the 48 contiguous states or
Hawaii, or any importer of gasoline or diesel fuel into the 48 contiguous states or Hawaii during a compliance period
(40 C.F.R. §80.1406(a)(1)). A renewable identification number (RIN) is a unique 38-character number that is issued (in
accordance with EPA guidelines) by the biofuel producer or importer at the point of biofuel production or the port of
importation (40 C.F.R. §80.1425). T here are five different RIN types which are assigned based on a fuel’s “ D-code”
depending upon the specific type of fuel (40 C.F.R. §80.1425). For more information, see CRS T estimony T E10026,
Background on Renewable Identification Num bers under the Renewable Fuel Standard , by Brent D. Yacobucci.
24 As will be discussed later in this section, some renewable fuels can generate more RINs per gallon of fuel.
25 T he statute requires the EPA Administrator to express the annual renewable fuel obligation in percentages. 42 U.S.C.
7545(o)(3). For 2022, EPA reports the overall renewable fuel percentage standard is 11.59%, the advanced biofuel
percentage standard is 3.16%, the biomass-based diesel percentage standard range is 2.33%, and the cellulosic biofuel
percentage standard range is 0.35%. U.S. Environmental Protection Agency, “ Renewable Fuel Standard (RFS)
Program: RFS Annual Rules,” 87 Federal Register 39603, July 1, 2022. If applicable, the annual RVO calculation for
an obligated party may include a carry-over deficit from the previous year.
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3. the separated RIN may be submitted for compliance, traded, or banked for future
use.
RINs are valid for use to demonstrate compliance in the year they are generated and the following
year.26 RINs may be used by the party that generates them or they may be traded with other
parties. The EPA Moderated Transaction System (EMTS) is used to register RIN transactions.
An obligated party incurs a deficit if they are unable to submit enough RINs to meet their RVO
for that compliance period. An obligated party may carry a deficit due to a variety of reasons
(e.g., financial constraints for purchasing RINs, an obligated party miscalculating how much gas
or diesel they would produce). Obligated parties may carry a deficit from one year to the next, but
in the year following the deficit, the obligated party must meet compliance for that year’s
renewable fuel volume requirement and purchase or generate enough credits to satisfy the deficit
from the previous year.27
Different biofuels are not treated equal y within the RFS. The categories are nested within each
other, such that some fuels qualify for multiple categories (e.g., cel ulosic ethanol), while others
(mainly corn starch ethanol) may only be used to meet the overal RFS but not the advanced
category or its nested subcategories.28 For example, a gal on of cel ulosic biofuel may be used to
meet the cel ulosic biofuel mandate, the advanced biofuel mandate, or the total renewable fuel
mandate, possibly making it a more highly valued fuel.29
In addition, some biofuels generate more RINs per volume than others because of the difference
in the fuel’s energy content. This difference is accounted for by a metric referred to as the
equivalence value (EV) of the biofuel.30 The EV of a renewable fuel represents the number of
gal ons that can be claimed for compliance purposes for every physical gal on of renewable fuel
used, and it is general y the ratio of the energy content of a gal on of the fuel to a gal on of
ethanol. For example, biodiesel has an EV of 1.5 when being used as an advanced biofuel, so
1,000 physical gal ons of biodiesel would equal 1,500 RIN gal ons of advanced biofuels.31
The 2020, 2021, and 2022 Final Rule
EPA published the final rule for the 2020, 2021, and 2022 RFS volume requirements in the
Federal Register on July 1, 2022.32 EPA reduced the total renewable fuel volume requirements
from what is required by statute for 2020, 2021, and 2022 (see Table 1). EPA reports it is
“utilizing the cel ulosic waiver authority along with the ‘reset’ waiver authority to reduce the

26 40 C.F.R. §80.1427(a)(6)(i) in the EPA RFS regulations.
27 42 U.S.C. §7545(o)(5)(D).
28 Although a gallon of a biofuel may be used to fulfill individual sub-requirements or the overall requirement, each
gallon counts once against the overall renewable fuel use obligation.
29 T he value of any biofuel within the RFS depends on the RIN price at a given time. As different categories of RINs
are used to meet the various standards, there is often a price difference between RINs (e.g., advanced biofuel RINs are
generally more expensive than conventional biofuel RINs). However, there is no public market for RINs, so real -time
price data are difficult to obtain. EPA does provide historical weekly RIN price data. Environmental Protection
Agency, RIN Trades and Price Inform ation, July 7, 2022.
30 40 C.F.R. §80.1415.
31 All equivalence values (EVs) are in relation to the energy content of ethanol. The EV for ethanol is 1.0. One gallon
of biodiesel contains roughly 1.5 times the energy of one gallon of ethanol, and thus has an EV of 1.5.
32 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register 39600, July 1, 2022.
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The Renewable Fuel Standard (RFS): An Overview

applicable volumes for 2020, 2021, and 2022 for total renewable fuel, advanced biofuel,
and cel ulosic biofuel.”33 EPA reports that, for 2020, it set the volumes based on the actual
volumes of renewable fuel and transportation fuel used during that year.34 For 2021, EPA reports
it set the volumes equal to the actual volumes of cel ulosic biofuel, advanced biofuel, and total
renewable fuel that were used in that year.35 EPA reports that, for 2022, it set volumes based on
the statutory factors and “our assessment of the ability for the RFS program to incentivize
increased production and use of renewable fuel in 2022,” among other items.36 EPA reports the
retroactive reduction of the 2020 volume requirements is necessary due to “significant and
unanticipated events” that occurred following the release of the 2020 final rule.37 These events
include the COVID-19 pandemic—which led to a drop in transportation fuel demand—and lower
than expected gasoline and diesel volume exemptions from the 2020 RFS obligations stemming
from smal refinery exemptions (SREs).38
EPA addresses other implementation duties in the final rule. For instance, EPA addresses the court
remand of the 2014-2016 final rule by adding a supplemental volume obligation of 250 mil ion
gal ons for 2022 (EPA stated that it intends to establish an additional supplemental volume of 250
mil ion gal ons for 2023 as wel ).39 Additional y, EPA reports it is al owing the use of certain
biointermediates to produce qualifying renewable fuels for the RFS program.40 In short,
biointermediates are feedstocks made from renewable biomass that are general y constructed into
a more useable and easily transportable form at one facility and converted to fuel at a different
facility. EPA reports that technologies that employ biointermediates could “provide an
opportunity for the future growth in production of the cel ulosic biofuels required under the RFS
program.”41 Lastly, EPA is implementing regulatory changes, including the treatment of
confidential business information under the program,42 among other actions.

33 Ibid. T he statute granted EPA the authority to “reset” the RFS given certain conditions starting in 2016. For more
information on waiver authority for the RFS, see CRS Report R44045, The Renewable Fuel Standard (RFS): Waiver
Authority and Modification of Volum es, by Kelsi Bracmort .
34 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules, ” 87 Federal
Register 39602, July 1, 2022.
35 Ibid.
36 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register 39603, July 1, 2022.
37 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register 39602, July 1, 2022.
38 For more information on small refinery exemptions, see CRS Report R46244, The Renewable Fuel Standard (RFS):
Frequently Asked Questions About Sm all Refinery Exem ptions (SREs), by Kelsi Bracmort .
39 In short, the court decision requires EPA to address 500 million gallons of total renewable fuel that EPA reduced
from the 2016 mandate by improperly using the RFS general waiver author ity. U.S. Environmental Protection Agency,
“Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal Register 39603, July 1, 2022.
40 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register 39604, July 1, 2022.
41 Ibid.
42 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register 39652, July 1, 2022.
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Table 1. Renewable Fuel Standard Statute and EPA Final Volumes
(bil ions of gal ons)
Due Date
Cap on
and Actual
Convention
Date of
Portion from Advanced Biofuels
al Biofuel
Final Rule
Total
Total
Biomass-
Statute
Renewable
Advanced
Cellulosic
Based
Year
or Final
Fuel
Biofuels
Biofuel
Diesel

2010
S
12.95
0.95
0.1000
0.65
12.00
Nov. 2009

F
12.95
0.95
0.0065
1.15
12.00
Feb. 2010
2011
S
13.95
1.35
0.2500
0.80
12.60
Nov. 2010

F
13.95
1.35
0.0060a
0.80
12.60
Nov. 2010
2012
S
15.20
2.00
0.5000
1.00
13.20
Nov. 2011

F
15.20
2.00
0.0105b
1.00
13.20
Dec. 2011
2013
S
16.55
2.75
1.0000
≥1.00
13.80
Nov. 2012

F
16.55
2.75
0.0008
1.28
13.80
Aug. 2013
2014
S
18.15
3.75
1.7500
≥1.00
14.40
Nov. 2013

F
16.28
2.67
0.0330
1.63
13.61
Nov. 2015
2015
S
20.50
5.50
3.0000
≥1.00
15.00
Nov. 2014

F
16.93c
2.88
0.1230
1.73
14.05
Nov. 2015
2016
S
22.25
7.25
4.2500
≥1.00
15.00
Nov. 2015

F
18.11c
3.61
0.2300
1.90
14.50
Nov. 2015
2017
S
24.00
9.00
5.5000
≥1.00
15.00
Nov. 2016

F
19.28
4.28
0.3110
2.00
15.00
Nov. 2016
2018
S
26.00
11.00
7.0000
≥1.00
15.00
Nov. 2017

F
19.29
4.29
0.2880
2.10
15.00
Nov. 2017
2019
S
28.00
13.00
8.5000
≥1.00
15.00
Nov. 2018

F
19.92
4.92
0.4180
2.10
15.00
Nov 2018
2020
S
30.00
15.00
10.5000
≥1.0
15.00
Nov. 2019

F
17.13
4.63
0.51
2.43
12.50
Jul. 2022
2021
S
33.00
18.00
13.5000
≥1.00
15.00
Nov. 2020

F
18.84
5.05
0.56
2.43
13.79
Jul. 2022
2022
S
36.00
21.00
16.0000
≥1.00
15.00
Nov. 2021

F
20.63
5.63
0.63
2.76
15.00
Jul. 2022
(+ 0.25)d
2023
S
To Be Determined by the EPA Administratore
and
beyond
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Source: Energy Independence and Security Act of 2007 (EISA; P.L. 110-140); Final rules are available at U.S.
Environmental Protection Agency, Regulations and Volume Standards for Renewable Fuel Standards, July 7, 2022,
https://www.epa.gov/renewable-fuel-standard-program/regulations-and-volume-standards-renewable-fuel-
standards.
Notes: S = Statute, F = Final. Al volumes are ethanol equivalent, except for biomass-based diesel, which is
actual. The 2010 biomass-based diesel requirement of 1.15 bil ion gal ons equals the 0.5 bil ion gal on
requirement for 2009 plus the 0.65 bil ion gal on requirement for 2010. Cap on Conventional Biofuel = Total
Renewable Fuel – Total Advanced Biofuel. The total advanced biofuel requirement equals the sum of cel ulosic
biofuel and biomass-based diesel (both of which have annual volume targets provided in statute and are identified
in Table 1 in italics) plus other advanced biofuel (which does not have an annual volume target provided in
statute).
a. EPA rescinded the 2011 cel ulosic biofuel standard.
b. RFS Final Rule 2012, Federal Register, January 9, 2012. Subsequently vacated under American Petroleum
Institute v. EPA, D.C. Cir., No. 12-1139, 1/25/13.
c. The D.C. Circuit Court vacated EPA’s 2016 total renewable fuel volume requirement and remanded the
2015 final rule to EPA for reconsideration. Americans for Clean Energy v. EPA, No. 16 -1005, 2017 U.S. App.
LEXIS 13692, at *4-5 (D.C. Cir. July 28, 2017).
d. Supplemental standard of 250 mil ion gal ons for 2022 to partial y address court remand of 2016 standard.
EPA reports it intends to establish an additional supplemental volume of 250 mil ion gal ons for 2023 in a
subsequent action. U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS
Annual Rules,” 87 Federal Register, July 1, 2022.
e. The EPA Administrator is to coordinate with the Secretaries of Energy and Agriculture and take into
account an analysis of certain factors to determine the volume amounts. 42 U.S.C. §7545(o)(2)(B)(i ).
RFS Implementation Issues
Implementation of the RFS has been complex, and compliance with some of its parts has been
chal enging, according to some stakeholders. This section briefly explains some of the general
concerns and chal enges with implementing the RFS.
Administering Agency
EPA administers the RFS.43 This responsibility includes evaluating renewable fuel pathways
eligible for the RFS.44 In addition, EPA is required to evaluate the ability of the biofuel industry to
produce enough fuel to meet the annual volume standard, release an annual volume standard
based on its research findings,45 and ensure that annual compliance by obligated parties is met.
Al of the above must be completed annual y, in compliance with any directives from court
decisions and taking into consideration comments from other government agencies and the

43 Although the RFS is administered by EPA, programs under other federal departments may indirectly assist biofuel
production that may be used to meet the mandate. For example, the U.S. Department of Agriculture (USDA) provides
resources and support for biofuel feedstock development and supply, biofuel infrastructure development, advanced
biofuel production, and more (e.g., Rural Energy for America Program, Advanced Biofuel Payment Program, and
Higher Blends Infrastructure Incentive Program). For more information on energy programs administered by USDA,
see CRS Report R45943, The Farm Bill Energy Title: An Overview and Funding History, by Kelsi Bracmort .
44 A fuel pathway consists of three components: a biomass feedstock, a biofuel production process, and a fuel type
(e.g., ethanol made from corn starch using a dry mill production process). T he fuel pathway is assigned to a renewable
fuel category (known by its D code provided in T able 1 of 40 C.F.R. §80.1426 in the RFS regulations) which signifies
which RIN the biofuel is eligible for to be in compliance with the RFS. EPA maintains a list of approved fuel pathway
and fuel pathway petitions on its website (https://www.epa.gov/renewable-fuel-standard-program/approved-pathways-
renewable-fuel).
45 Frequently, EPA has approved annual standards for some biofuels different from what was originally scheduled in
statute.
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public. These responsibilities could be viewed as an addition to EPA’s regulatory workload and
have required EPA to develop new capabilities to carry them out.
In the years following the 2010 issuance of the amended RFS final rule,46 EPA has used its waiver
authorities to set annual volume requirements for cel ulosic biofuel, total advanced biofuel, and
total renewable fuel below the amounts stated in the statute.47 Legal chal enges have been brought
against the EPA regarding some of these annual fuel volume requirements and the projections on
which they were based. For instance, the American Petroleum Institute objected to EPA’s 2012
cel ulosic biofuel production projection methodology, among other things, and chal enged it in
court. The federal court vacated the 2012 cel ulosic biofuel standard and provided principles for
EPA to apply to future annual projections.48 Likewise, Americans for Clean Energy and other
petitioners chal enged various aspects of the final rule that set the volume requirements and
projections for 2014-2016 and 2017 for biomass-based diesel, including EPA’s interpretation of
“inadequate domestic supply” in exercising its general waiver authority to reduce the total
volume requirements. The D.C. Circuit held that EPA’s interpretation of “inadequate domestic
supply” was not reasonable and that EPA had improperly exercised its waiver authority as a
result. It vacated EPA’s 2016 total renewable fuel volume requirement and remanded the final
rule to EPA for reconsideration consistent with the court’s decision.49
In some instances, the timing of EPA’s RFS regulatory actions, such as the annual announcement
of the renewable fuel volume requirements, has not met statutory deadlines (see Table 1).50 A
lack of timely rulemaking combined with inaccurate volume projections could affect private
investment, according to some advanced biofuel producers.51 Additional y, the amount of time it
takes the agency to approve new fuel pathways and register new facilities has been raised in
public comments to proposed RFS rules.52 Slow approval could potential y stifle investment and
production of new fuels. Further, prolonged processing time for some program enhancement
rules—such as the proposed Renewables Enhancement and Growth Support rule (REGS rule)—
may impede the growth of the program.53

46 EPA, “Regulation of Fuels and Fuel Additives: Changes to Renewable Fuel Standard Program; Final Rule,” 75
Federal Register 14670, March 26, 2010.
47 For more discussion, see CRS Report R44045, The Renewable Fuel Standard (RFS): Waiver Authority and
Modification of Volum es, by Kelsi Bracmort .
48 American Petroleum Institute v. EPA, 706 F.3d 474 (D.C. Cir. 2013). More discussion of this legal challenge is in
CRS Report R41106, The Renewable Fuel Standard (RFS): Cellulosic Biofuels, by Kelsi Bracmort .
49 Americans for Clean Energy v. EPA, 864 F.3d 691, 737 (D.C. Cir. 2017).
50 Under the Clean Air Act, each year’s standards are required to be announced by November 30 of the previous year.
EPA’s late announcement of the annual requirements may be due to the depth of the analysis (e.g., difficulty in
obtaining reliable and timely information from the industry) or to other factors.
51 Written statement by Nebraska Governor Pete Ricketts, Chairman, Governors’ Biofuels Coalition, U.S. Environment
Protection Agency, Public Hearing, Proposed Renewable Fuel Standard Program : Standards for 2018 and Biom ass -
Based Diesel Volum e for 2019, Washington, DC, August 1, 2017.
52 EPA, Renewable Fuel Standard Program —Standards for 2020 and Biomass-Based Volume for 2021: Response to
Com m ents, EPA-420-R-19-018, December 2019, p. 30-32; U.S. Environmental Protection Agency, Renewable Fuel
Standard (RFS) Program : RFS Annual Rules Response to Com m ents, EPA-420-R-22-009, June 2022, p. 322.
53 EPA issued the proposed REGS rule in November 2016. T he REGS rule would modify RFS program regulations to
increase production of cellulosic and other advanced biofuels, among other things. EPA requested comment on
multiple provisions of the proposed REGS rule in the 2020 RFS proposed rule and finalize d some of those provisions
in the 2020 final rule. EPA did the same for the 2020, 2021 , and 2022 RFS rule where it finalized the use of certain
biointermediates which was also discussed in the REGS rule. It is not clear when EPA will act on those provision s not
finalized in the 2020 final rule. U.S. Environmental Protection Agency, “Renewables Enhancement and Growth
Support Rule: Proposed Rule,” 81 Federal Register 80828, November 16, 2016; U.S. Environmental Protection
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Lastly, EPA has the authority to “reset” the RFS. The “reset” authority al ows the EPA
Administrator to adjust the applicable volumes of the RFS for future years starting in 2016 if
certain conditions are met.54 EPA reports in the final rule for the 2020, 2021, and 2022 volumes
that the “reset” provision for the RFS has been triggered for three of the four renewable fuel
categories identified in statute.55 EPA reports the “conditions for resetting cel ulosic biofuel
volumes were met by the 2010 annual standard, which reduced the applicable cel ulosic biofuel
volume by at least 50 percent.”56 EPA reports the “conditions for resetting advanced biofuel
volumes were met by the 2014 and 2015 annual standards, which reduced the applicable
advanced biofuel volume by at least 20 percent for two consecutive years.”57 And, EPA reports
the “conditions for resetting total renewable fuel volumes were met by the 2018 and 2019 annual
standards, which reduced the applicable total renewable fuel volume by at least 20 percent for
two consecutive years.”58
Qualifying Biofuels
As noted above, there are a number of nested categories within the RFS; a fuel may qualify as a
biofuel for one or more portions of the mandate.59 Difficulty by some advanced biofuel producers
in understanding which advanced biofuels qualify for the RFS can lead to chal enges in
determining how compliance is being met.60
Not al fuels from a renewable source are eligible under the RFS. The RFS operates as a biofuel
standard, with priority assigned to liquid transportation fuels from biomass feedstocks.61 Other
renewable sources (e.g., wind) do not qualify. Before a fuel can generate RFS RINs, however,

Agency, “Renewable Fuel Standard Program: Standards for 2020 and Biomass-Based Diesel Volume for 2021 and
Other Changes,” 85 Federal Register 7016, February 6, 2020; and U.S. Environmental Protection Agency, “Renewable
Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal Register 39636, July 1, 2022.
54 For more discussion of the reset provision, see CRS Report R44045, The Renewable Fuel Standard (RFS): Waiver
Authority and Modification of Volum es, by Kelsi Bracmort .
55 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register 39606, July 1, 2022.
56 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register 39607, July 1, 2022.
57 Ibid.
58 Ibid.
59 Approved RFS fuels and feedstocks are provided by EPA at https://www.epa.gov/renewable-fuel-standard-program/
approved-pathways-renewable-fuel.
60 For example, there were questions by some about the eligibility of algae-based biofuels for the RFS. For more
information, see CRS Report R42122, Algae’s Potential as a Transportation Biofuel, by Kelsi Bracmort .
61 In July 2014, EPA approved new cellulosic and advanced biofuel pathways to include the production of compressed
natural gas, liquefied natural gas, and electricity from biogas from landfills, municipal waste-water treatment facility
digesters, agricultural digesters, and separated municipal solid waste digesters. Co mpliant fuels for the RFS also
include heating oil and jet fuel. See EPA, “ Regulation of Fuels and Fuel Additives: RFS Pathways II, and T echnical
Amendments to the RFS Standards and E15 Misfueling Mitigation Requirements; Final Rule,” 79 Federal Register
42128, July 18, 2014. EPA, “ Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard
Program – Final Rule,” 78 Federal Register 62462, October 22, 2013.
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that fuel pathway must be approved by EPA;62 according to some in Congress and some advanced
biofuel producers, that process can take a considerable amount of time for some fuels.63
Lastly, some may view the RFS as a biofuel production mandate. The statutory language does not
mandate the production of biofuels; rather, it mandates the use of biofuel. However, it could be
argued that it is not possible to use a fuel that is not being produced and that the RFS therefore
indirectly creates a demand for certain biofuels and thus stimulates their production.
Cellulosic Biofuel Production
By statute, cel ulosic biofuel is targeted to comprise approximately 44% of the total renewable
fuel mandate in 2022. However, the annual cel ulosic biofuel volume target established by
Congress is not being met. Actual cel ulosic biofuel production volumes (e.g., cel ulosic ethanol)
are below the expectations set when the law was passed. The statute contains a cel ulosic biofuel
waiver authority that, in short, al ows the EPA Administrator to reduce the cel ulosic biofuel
mandate when the projected production capacity for a given year is less than the volume required
in the statute.64 For instance, in 2022, the statute requires 16.0 bil ion gal ons of cel ulosic biofuel.
EPA set the 2022 target volume at 630 mil ion gal ons for 2022. This gap is due to several factors,
including lack of private investment, logistical chal enges, technology setbacks, and uneven
support from the federal government.65 These factors, coupled with the fact that annual volumes
in the statute were established when market conditions for raising investment capital for new
biofuel technologies were more favorable, may suggest unrealistic targets for some advanced
biofuels. These production limitations have raised questions about whether the statutory cel ulosic
biofuel volumes are attainable.
Blend Wall
The “blend wal ” is a term used to describe the upper limit to the total amount of ethanol that can
be blended into U.S. gasoline and stil maintain automobile performance and comply with other
provisions of the Clean Air Act. The blend wal has been viewed by many to be in direct conflict
with the biofuel volumes mandated in the RFS.66 Thus far, the largest volume being met under the
RFS is for the implied conventional biofuel segment of the mandate, met mainly with corn starch
ethanol blended into gasoline. Due to a variety of factors (e.g., automaker warranty coverage,
fueling station infrastructure, etc.), ethanol content in gasoline is general y limited to 10% (E10).

62 For more information on the fuel pathways for the RFS and the pathway petition process, see U.S. Environmental
Protection Agency, Fuel Pathways under Renewable Fuel Standard , July 7, 2022, https://www.epa.gov/renewable-
fuel-standard-program/fuel-pathways-under-renewable-fuel-standard.
63 Biomass Power Association, “RFS Power Coalition Commends Rep. John Garamendi for Introducing Bill Requiring
EPA Action on eRINs,” press release, November 9, 2021. Sen. John T hune, “T hune, Shaheen Reintroduce Bill to
Advance Renewable Fuel T echnologies,” press release, February 4, 2 021. Rep. Cheri Bustos, “Streamlining Advanced
Biofuels Registration Act of 2020,” press release, November 17, 2020; Biotechnology Innovation Organization, “2018
RFS Volumes Set Back Growth in Cellulosic Biofuels,” press release, November 30, 2017, https://www.bio.org/press-
release/2018-rfs-volumes-set-back-growth-cellulosic-biofuels; “ BIO Encourages EPA to Speed Approvals of New
Biofuel Pathways,” Business Wire, March 31, 2014, https://www.businesswire.com/news/home/20140331006205/en/
BIO-Encourages-EPA-Speed-Approvals-New-Biofuel.
64 42 U.S.C. 7545(0)(7)(D).
65 For more discussion, see CRS Report R41106, The Renewable Fuel Standard (RFS): Cellulosic Biofuels, by Kelsi
Bracmort .
66 For more discussion, see CRS Report R40445, Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol
“Blend Wall”, by Kelsi Bracmort.
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With a relatively fixed supply of gasoline, the amount of ethanol that can be supplied this way is
also limited.
In the past, under economic conditions at that time (i.e., 2018 and 2019), the blend wal was a
concern to some, but it may not have been as significant an impediment to immediate fuel
consumption as previously considered.67 In December 2019, EPA reported “the E10 blend wal is
not the barrier that some commenters believe it to be.”68 However, a significant reduction in
gasoline consumption would likely require a reduction in the amount of ethanol needed to be
blended into the gasoline. The U.S. Energy Information Administration (EIA) reported that 2020
U.S. motor gasoline consumption decreased to its lowest level since 1997, mainly due to
responses to the COVID-19 pandemic.69 EIA also reported that ethanol production changes
followed motor gasoline production changes—particularly at the beginning of the COVID-19
pandemic.70 EPA responded to these 2020 decreases, in part, by retroactively adjusting the 2020
volumes and standards based on the actual volumes of renewable fuel and transportation fuel used
in the U.S in 2020.”71 It is not clear how long the COVID-19 pandemic wil last and how the
pandemic may affect future motor gasoline consumption.72 It is also not clear what effect the
Russian invasion of Ukraine as wel as gasoline prices wil have on future motor gasoline
consumption. Thus, it is difficult to determine what national or international events could
potential y impact the blend wal and RFS compliance, among other things.
There are some possible approaches that could al eviate blend wal concerns. One option is to
blend higher levels of ethanol into conventional gasoline. In 2011, EPA granted a Clean Air Act
waiver that al ows gasoline to contain up to 15% ethanol for use in model year 2001 and newer
light-duty motor vehicles.73 However, limited demand, legal constraints limiting E15 sales to
winter months, and infrastructure and automobile warranty concerns have precluded widespread
offering and purchase of E15.74 Nonetheless, widespread use of E15 could potential y postpone
the blend wal for some time.
Another option to address the blend wal would be increasing the use of ethanol in flexible-fuel
vehicles capable of using E85, a gasoline-ethanol blend containing 51% to 83% ethanol.75

67 Sen. James M. Inhofe, “Inhofe, Senators Urge RFS Policy to Reflect Market Realities,” press release, May 1, 2019;
Renewable Fuels Association, “DOE Data Show 31 States Broke T hrough So -Called ‘Blend Wall’ in 2016,” press
release, February 2, 2018, https://ethanolrfa.org/2018/02/doe-data-show-31-states-broke-called-blend-wall-2016/.
68 EPA, Renewable Fuel Standard Program —Standards for 2020 and Biomass-Based Volume for 2021: Response to
Com m ents, EPA-420-R-19-018, December 2019.
69 U.S. Energy Information Administration, U.S. Petroleum Consumption Decreased to a 25-Year Low in 2020, August
5, 2021. U.S. Energy Information Administration (EIA) data for motor gasoline supply shows a steep decline in late
March 2020. U.S. Energy Information Administration, Weekly U.S. Product Supplied of Finished Motor Gasoline,
January, 10, 2022, https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=WGFUPUS2&f=W.
70 U.S. Energy Information Administration, U.S. Fuel Ethanol Production and Inventory Changes Have Largely
Followed Motor Gasoline, June 8, 2020.
71 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal
Register 39602, July 1, 2022.
72 T he U.S. Energy Information Administration (EIA) reports that “COVID-19 continues to be a major source of
uncertainty, especially in the near term.” U.S. Energy Information Administration, Annual Energy Outlook2022
(AEO2022), March 3, 2022.
73 For more information, see U.S. Environmental Protection Agency, Ethanol Waivers (E15 and E10), July 7, 2022,
https://www.epa.gov/gasoline-standards/ethanol-waivers-e15-and-e10.
74 In 2022, EPA issued multiple emergency waivers to allow E15 to be sold during the summer. For more discussion,
see CRS Insight IN10979, Year-Round Sale of E15, by Kelsi Bracmort .
75 T he U.S. Department of Energy (DOE) reports that as of 2018 there were more than 21 million FFV in the United
States. U.S. Department of Energy Alternative Fuels Data Center, Flexible Fuel Vehicles, July 7, 2022. T he U.S.
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However, there are infrastructure constraints with the use of E85. For example, the number of
E85 fueling stations is limited.76 There are government infrastructure initiatives aimed at
increasing the availability of E15 and other higher ethanol-gasoline blends. For example, the U.S.
Department of Agriculture (USDA) administers the Higher Blends Infrastructure Incentive
Program (HBIIP), with an overal goal to increase the sales and use of higher blends of ethanol
and biodiesel.77 USDA reports the program wil do this, in part, by “sharing the costs related to
and/or offering sales incentives for the instal ation of fuel pumps, related equipment, and
infrastructure.”78
Other Factors
The RFS is not a stand-alone program. The implementation and impacts of the program are
affected by many factors that are not easily predicted or controlled. For example, cel ulosic
biofuel production, at a minimum, requires conversion technology, which itself requires technical
expertise and time to ramp up to commercial scale. The large quantity of biomass feedstocks
needed to produce such biofuels requires factors such as appropriate weather conditions and an
expectation of stable markets for feedstock commodities. Further, some types of biofuel
production thus far have been sensitive to the availability of tax incentives in order to be
economical y feasible (e.g., biodiesel).79 Unexpected occurrences (e.g., drought, failed
technology, tax incentive expiration, trade disputes) could potential y impact an entire industry,
especial y for some advanced biofuels in nascent industries compared to conventional
transportation fuels.
Congressional Issues
The RFS was established in 2005 at a time when Congress foresaw the need to diversify the
country’s energy portfolio, strengthen the economy of rural communities that could contribute to
biofuel production, bolster U.S. standing in an emerging segment of the energy technology
market, and protect the environment, among other objectives. The RFS was subsequently
expanded in 2007. Since then, some components of the RFS (e.g., corn starch ethanol, biomass-
based diesel) have progressed steadily toward meeting statutory requirements and other
components (e.g., cel ulosic biofuel) have not.
There has been perennial legislative interest, executive activity, and litigation regarding the RFS.
Several factors have led to congressional interest in the RFS—including the statutory
requirements, the implementation process, stakeholder interests, complementary programs,
actions of federal agencies, and agricultural trade issues, among other things. Further, the RFS is
a program with elements and objectives that are interpreted differently by the parties that must
abide by the underlying statute.

Department of T ransportation reports there were 250.7 million light -duty vehicles in the United States in 2018. U.S.
Department of T ransportation Bureau of T ransportation Statistics, Num ber of U.S. Aircraft, Vehicles, Vessels, and
Other Conveyances, July 7, 2022.
76 T he U.S. Department of Energy reports there were 4,257 E85 fueling stations as of July 2022. U.S. Department of
Energy, Ethanol Fueling Station Locations, July 7, 2022, https://afdc.energy.gov/fuels/ethanol_locations.html#/
analyze?fuel=E85.
77 For more information about HBIIP, see the HBIIP website at https://www.rd.usda.gov/hbiip.
78 U.S. Department of Agriculture, “Announcement of Future Competitive Grant Funds Availability for Higher Blends
Infrastructure Incentive Program (HBIIP) for Fiscal Year 2020,” 85 Federal Register 11946, February 28, 2020.
79 For example, see U.S. Energy Information Administration, U.S. Biomass-Based Diesel Tax Credit Renewed Through
2022 in Governm ent Spending Bill, January 28, 2020.
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Among the items Congress may opt to consider (in no particular order) as it continues to debate
the merits and chal enges of the RFS:
 Timing and EPA discretion. 2022 is the last year for which the RFS program
has annual volumes specified in statute. After 2022, the EPA Administrator is to
determine the annual volume amounts.
 Reset. The EPA Administrator has the authority to modify the volume
requirements for future years for the total renewable fuel, advanced biofuel, and
cel ulosic biofuel categories if certain statutory criteria are met.
 Fuel pathways. Fuel pathways must be approved by EPA in order for a fuel to be
eligible for the RFS. The time it takes and the resources EPA has to approve the
pathways are unclear.
 Volume targets. The statutory targets have not been met for the last several years
for three of the four fuel categories: total renewable fuel, advanced biofuel, and
cel ulosic biofuel. The statutory target for biomass-based diesel has been met as
has the implied target for conventional biofuel.80
 Environmental impact. EPA is to provide Congress with a report every three
years that assesses the impact of the RFS on environmental issues and resource
conservation issues, among other things.81 There are various perspectives about
the environmental impact of the RFS.82
 RFS compliance. A tradeable credit system is used to ensure obligated parties
comply with the RFS. At times, the availability and cost of the credits (i.e., RINs)
and the transparency of the market have been a concern to some.83
 Small refinery exemptions. Smal refineries may petition the EPA Administrator
for an exemption from the RFS mandate if they can prove compliance would
subject them to disproportionate economic hardship.84 Some Members of
Congress question how EPA evaluates the petitions and how EPA accounts for
such exemptions, among other things.

80 EPA reduced the implied target for conventional biofuel for 2020 and 2021. U.S. Environmental Protection Agency,
“Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal Register 39600, July 1, 2022.
81 EISA Section 204. In May 2022, EPA announced a public comment period on the pool of candidates selected for the
external peer review of the Biofuels and the Environment: Third T riennial Report to Congress. In addition, EPA
reported that the third triennial report will build “on the previous two reports and provides an update on the impacts to
date of the RFS Program on the environment” and that the third report will include “new analyses not previously
included in the first and second reports.” U.S. Environmental Protection Agency, “Notice of Public Comment Period on
the Pool of Candidate Peer Reviewers for the Biofuels and the Environment: T hird T riennial Report to Congress, ” 87
Federal Register 27634, May 9, 2022. U.S. Environmental Protection Agency, Biofuels and the Environm ent: The
Second Triennial Report to Congress, EPA/600/R-18/195, June 29, 2018. U.S. Environmental Protection Agency,
Biofuels and the Environm ent: First Triennial Report to Congress, EPA/600/R-10/183F, December 2011.
82 U.S. Government Accountability Office, Renewable Fuel Standard: Information on Likely Program Effects on
Gasoline Prices and Greenhouse Gas Em issions, GAO-19-47, May 2019.
83 For more information, see U.S. Energy Information Administration, Renewable identification number prices for
ethanol and biom ass-based diesel rem ain high, July 13, 2022 and U.S. Congress, House Committee on Energy and
Commerce, Subcommittee on Environment, Background on Renewable Identification Num bers under the Renewable
Fuel Standard, T estimony of Brent Yacobucci, 115th Cong., July 25, 2018.
84 For more information on small refinery exemptions, see CRS Report R46244, The Renewable Fuel Standard (RFS):
Frequently Asked Questions About Sm all Refinery Exem ptions (SREs) , by Kelsi Bracmort .
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Author Information

Kelsi Bracmort

Specialist in Natural Resources and Energy Policy

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan
shared staff to congressional committees and Members of Congress. It operates solely at the behest of and
under the direction of Congress. Information in a CRS Report should n ot be relied upon for purposes other
than public understanding of information that has been provided by CRS to Members of Congress in
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Congressional Research Service
R43325 · VERSION 48 · UPDATED
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