CRS Insights
Maps of 2015 Individual Exchange Enrollment by Zip Code
Namrata K. Uberoi, Analyst in Health Care Financing (nuberoi@crs.loc.gov, 7-0688)
James C. Uzel, Geospatial Information Systems Analyst (juzel@crs.loc.gov, 7-6830)
May 21, 2015 (IN10282)
The 2010 Patient Protection and Affordable Care Act (ACA; P.L. 111-148, as amended) allows certain individuals
to purchase health plans through health insurance exchanges (also known as marketplaces). According to April
2015 enrollment figures, 11.7 million individuals selected a health insurance plan between November 15, 2014,
and February 22, 2015.
This Insight presents a tool to examine exchange enrollment information by zip code with additional geographic
boundaries. Table 1 presents data on exchange enrollment for all states and includes hyperlinks to maps of
exchange enrollment by zip code for 37 states. Each map includes an option to overlay county and congressional
district boundaries. The maps are not an aggregation of exchange enrollment by county or congressional district;
rather, the maps present optional geographical boundaries over exchange enrollment by zip code.
Exchanges
Individual exchanges are marketplaces in which persons can shop for and purchase private health insurance
coverage. Exchanges may be established either by the state itself as a state-based exchange (SBE) or by the
Secretary of Health and Human Services (HHS) as a federally facilitated exchange (FFE). In states with FFEs, the
exchange may be operated solely by the federal government or in conjunction with the state.
For the 2015 coverage year, 34 states have FFEs, 13 states and the District of Columbia have SBEs, and 3 states
have SBEs but use the federal IT platform (see Figure 1).
The ACA requires that plans offered through an exchange are, for the most part, Qualified Health Plans (QHPs). In
general, to be certified as a QHP a plan must offer the essential health benefits, comply with cost-sharing limits,
and meet certain standards related to marketing, choice of providers, and plan networks. Each exchange is
responsible for certifying the plans it offers.
Figure 1. Health Insurance Exchange Types, 2015

Source: CRS illustration of HHS classification of health insurance exchange types.
Enrollment
Individuals are eligible to enroll in the exchanges during an Open Enrollment period. For the 2015 coverage year,
the Open Enrollment period was November 15, 2014, to February 15, 2015.
If an individual experiences a certain life change—such as having a baby—he or she may qualify for a Special
Enrollment Period. Furthermore, states or the federal government may initiate a Special Enrollment Period for
other circumstances.
Enrollment Data
Enrollment data are from HHS. The data represent pre-effectuated enrollment, which is the total number of unique
individuals who selected a QHP or were automatically reenrolled in a QHP but may or may not have submitted the
first premium payment for the 2015 coverage year. The data include enrollment during the 2015 Open Enrollment
period as well as Special Enrollment Period activity through February 22, 2015.
Exchange enrollment by state ranged from 12,625 enrollees in Hawaii to 1,596,296 enrollees in Florida (see Table
1). The most populous states (e.g., California, Texas, and Florida) had higher enrollee totals. Similarly, the least
populous states (e.g., Wyoming, Vermont, and Alaska) had lower enrollee totals.
HHS also provides exchange enrollment data by zip code for the 37 states using the federal IT platform (i.e.,
HealthCare.gov). These 37 states include the 34 states with FFEs and the 3 states with SBEs using the federal IT
platform. Approximately 8.8 million individuals residing in these 37 states selected a QHP between November 15,
2014, and February 22, 2015. These QHP selections are tabulated by zip code using the home address provided by
the exchange applicant. Zip code data were not available for approximately 2% of applicants. (Please contact the
Congressional Research Service for tabular zip code data arranged by state.)

Caveats
Mapping of the data by zip code is subject to the following caveats:
Zip code areas can cross counties, congressional districts, and/or states; thus, the distribution of enrolled
individuals in these geographies cannot be determined.
Because zip code geographic coverage areas are highly variable in size, the mapped data should not be
viewed as displaying enrollee densities. Very small zip code areas displayed on the maps may be obscured
due to scale or overlapping features or labels.
Due to privacy concerns, zip code-level enrollment data are not available for zip codes with 50 or fewer
eligible enrollees who have selected a QHP. As a result, the sum of QHP selections among zip codes within
a state using this dataset may not be equal to state-level totals provided in Table 1.
Table 1. Enrollment in Health Insurance Exchanges by State
(2015 Open Enrollment Period and Special Enrollment Period activity through February 22,
2015)
State
Type of Exchangea
Enrollmentb
Alabama
FFE
171,641
Alaska
FFE
21,260
Arizona
FFE
205,666
Arkansas
FFE
65,684
Californiac
SBE
1,412,200
Coloradoc
SBE
140,327
Connecticutc
SBE
109,839
Delaware
FFE
25,036
District of Columbiac
SBE
18,465
Florida
FFE
1,596,296
Georgia
FFE
541,080
Hawaiic
SBE
12,625
Idahoc
SBE
97,079
Illinois
FFE
349,487
Indiana
FFE
219,185
Iowa
FFE
45,162
Kansas
FFE
96,197
Kentuckyc
106,330

SBE
Louisiana
FFE
186,277
Maine
FFE
74,805
Marylandc
SBE
120,145
Massachusettsc
SBE
140,540
Michigan
FFE
341,183
Minnesotac
SBE
59,704
Mississippi
FFE
104,538
Missouri
FFE
253,430
Montana
FFE
54,266
Nebraska
FFE
74,152
Nevada d
SBE
73,596
New Hampshire
FFE
53,005
New Jersey
FFE
254,316
New Mexico d
SBE
52,358
New Yorkc
SBE
408,841
North Carolina
FFE
560,357
North Dakota
FFE
18,171
Ohio
FFE
234,341
Oklahoma
FFE
126,115
Oregon d
SBE
112,024
Pennsylvania
FFE
472,697
Rhode Islandc
SBE
31,337
South Carolina
FFE
210,331
South Dakota
FFE
21,393
Tennessee
FFE
231,440
Texas
FFE
1,205,174

Utah
FFE
140,612
Vermontc
SBE
31,619
Virginia
FFE
385,154
Washingtonc
SBE
160,732
West Virginia
FFE
33,421
Wisconsin
FFE
33,421
Wyoming
FFE
21,092
Total

11,688,074
Source: HHS, Health Insurance Marketplaces 2015 Open Enrollment Period: March
Enrollment Report, March 10, 2015.
a. State-based exchange (SBE) or federally facilitated exchange (FFE).
b. Enrollment data represent pre-effectuated enrollment, which is the total number of unique
individuals who selected or were automatically reenrolled in a qualified health plan but may or
may not have submitted the first premium payment.
c. Additional notes on this state's enrollment figures can be found in Appendix Table C1 of
HHS's March enrollment report.
d. State-based exchange that uses the federal IT platform.