No Surprises Act (NSA) Independent Dispute Resolution (IDR) Process Data Analysis for 2024

No Surprises Act (NSA) Independent Dispute Resolution (IDR) Process Data Analysis for 2024

November 26, 2025 (R48738)
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Contents

Summary

The No Surprises Act (NSA), part of the Consolidated Appropriations Act, 2021 (P.L. 116-260), established various consumer protections related to surprise billing—that is, circumstances in which individuals receive large, unexpected medical bills when they are unknowingly, and potentially unavoidably, treated by out-of-network (OON) providers. The law generally recognizes surprise billing circumstances to include OON emergency services, OON nonemergency services provided during a visit at an in-network facility, and OON air ambulance services. In those situations, the NSA generally limits the amount consumers pay for care and specifies a methodology to be used to determine how much insurers must pay OON providers for care if the parties cannot agree on the payment amount. Under this methodology, either the insurer or the provider may initiate an independent dispute resolution (IDR) process before a private arbitrator (i.e., an IDR entity). The IDR entity selects between the parties' payment offers after considering a list of statutory factors, including the qualifying payment amount (QPA) for an item or service, defined generally as an insurer's 2019 median in-network rate for the item or service, indexed for inflation.

The year 2024 marks the first year in which the IDR process was operational throughout the year without suspension, since it first began accepting dispute submissions in April 2022. This report, building on a prior CRS report analyzing 2023 data on IDR operations, reviews and analyzes data made publicly available by the Departments of Health and Human Services, Labor, and the Treasury—pursuant to NSA requirements—regarding IDR operations in calendar year 2024. In general, the data show an IDR process that was still maturing in 2024, as the year saw significant increases in the use of the IDR process (relative to 2022 and 2023) by providers; a large increase in the number of determinations made relative to 2023 and improvements in the amount of OON emergency/nonemergency service dispute determinations made within the generally required 33 business days (though a majority of determinations were still made outside of that window); and continued notable increases in payment determination amounts in certain medical specialties.

In 2024, more than 1.46 million federal IDR disputes were initiated, which was more than double the amount initiated in 2023 (679,156). Of this total, nearly 1.42 million disputes (approximately 97%) involved OON emergency/nonemergency services; the remaining 44,238 disputes (approximately 3%) involved OON air ambulance services. Disputes initiated in 2024 were slightly more concentrated in the second half of the year (approximately 58%), which may be attributable, in part, to delays in parties initiating disputes due to the Change Healthcare cybersecurity incident in February 2024. Providers initiated nearly all of the disputes in 2024 (over 99%). Providers with evidence of private equity affiliation continued to be heavy utilizers of the IDR process; several of those providers are among the top 10 initiating parties and initiated around 45%-55% of the disputes involving OON emergency/nonemergency services in each quarter and 65%-72% of the disputes involving OON air ambulance services in each quarter. However, the percentage of disputes involving OON emergency/nonemergency services initiated by those providers appeared to decrease relative to 2023, when providers among the top 10 initiating parties initiated at least two-thirds (67%) of such disputes each quarter. Meanwhile, 2024 saw a steady increase of disputes involving OON emergency/nonemergency services initiated by third-party representatives of providers who were among the top 10 initiating parties (from 13% in Q1 to 22% in Q4 of 2024).

Providers continued to demonstrate success with the IDR process in 2024 and improved on their success rate relative to 2023. This improvement was largely attributable to an increased number of determinations in which the insurer defaulted by not submitting an offer or paying applicable fees. In 2024, providers prevailed in a great majority of the payment determinations (approximately 85% in 2024; approximately 80% in 2023), and a similar majority of selected offers (approximately 85% in 2024; approximately 80% in 2023) were for an amount greater than the QPA. Insurers' offers were at or below the QPA in roughly half of disputes in 2024 (approximately 47%). Two specialties—(1) surgery and (2) neurology and neuromuscular procedures—saw significant increases in the median prevailing offer relative to the QPA from Q1 to Q4 of 2024, which continued (at a slightly slower pace) a trend that started in 2023. The median prevailing offer for disputes involving surgery increased from around 3 times the QPA in Q1 2023 to over 9 times the QPA in Q1 2024 to around 13 times the QPA in Q4 2024; for disputes involving neurology and neuromuscular procedures, the median prevailing offer increased from over 3 times the QPA in Q1 2023 to around 12 times the QPA in Q1 2024 to nearly 17 times the QPA in Q4 2024.


Overview

The year 2024 marked the second full year during which an independent dispute resolution (IDR) process—established by the No Surprises Act (NSA), part of the Consolidated Appropriations Act, 2021 (P.L. 116-260)—was operational. This IDR process resolves payment disputes between providers and private health insurers regarding certain out-of-network items or services furnished during surprise billing circumstances—that is, circumstances in which individuals receive large, unexpected medical bills when they are unknowingly, and potentially unavoidably, treated by out-of-network (OON) providers.1 More specifically, the law generally recognizes surprise billing circumstances to include OON emergency services, OON nonemergency services provided during a visit at an in-network facility, and OON air ambulance services. In those situations, the NSA generally limits the amount consumers pay for care and specifies a methodology to be used to determine how much insurers must pay OON providers for care.2

Under the federal payment methodology, when an insurer and an OON provider cannot agree on the relevant payment amount, either party may initiate an IDR process before a private arbitrator, referred to as an IDR entity.3 In a process commonly described as "baseball-style" arbitration,4 the insurer and provider each submit to the IDR entity an amount representing what the party believes the total price of care should be (i.e., a payment offer), and the IDR entity selects between the parties' payment offers after considering a list of statutory factors. The statutory factors include (1) the item's (or service's) qualifying payment amount (QPA), defined as an insurer's 2019 median in-network rate for a particular item or service furnished by a provider in the same or similar specialty, indexed for inflation, and (2) information related to specified "additional circumstances," including the provider's level of training, experience, and quality and outcome measurements.5

The IDR process became operational on April 15, 2022, when the Centers for Medicare & Medicaid Services (CMS) of the Department of Health and Human Services (HHS) opened the IDR portal, which accepts dispute submissions.6 In 2022 and 2023, the IDR process was marked by delays or disruptions, including periods of IDR portal suspension in response to several court decisions arising from legal challenges against agency rules implementing the process.7 The year 2024 was the first year in which the IDR portal was fully operational throughout the year, providing one indication of the process's stabilization. This report builds upon previous CRS analyses of IDR operations data made available—pursuant to statutory requirement8—by HHS to provide an overview and analysis of the 2024 data, primarily focusing on any trends observed relative to 2023.9

Dispute Initiation

How Many Disputes Were Initiated?

In 2024, more than 1.46 million federal IDR disputes were initiated. Of this total, nearly 1.42 million disputes (approximately 97%) involved OON emergency/nonemergency services and 44,238 disputes (approximately 3%) involved OON air ambulance services. The 2024 total is more than double the total number of disputes initiated in 2023 (679,156) and more than seven times the total number of disputes initiated in 2022 (200,112).10 The overall increase of initiated disputes from 2023 to 2024 is primarily attributable to increases in OON emergency or nonemergency service disputes (see Figure 1). OON air ambulance service disputes doubled from 2023 (22,116) to 2024 (44,238), but comprised 3% of all initiated disputes in both years.

As shown in Figure 1, the number of IDR initiated disputes for OON emergency/nonemergency services decreased from Q4 2023 through the first two quarters of 2024. This decrease may be attributable, in part, to a cybersecurity incident in February 2024 involving Change Healthcare, a health care technology company that facilitated transactions in the health care system.11 Among other effects, the incident—which involved a ransomware attack—disrupted communication between insurers and providers or facilities attempting to resolve OON surprise billing disputes. In response, HHS, the Department of Labor, and the Department of the Treasury (collectively, the Departments) allowed providers or facilities whose ability to initiate open negotiation with an insurer was affected by the Change Healthcare incident to initiate open negotiation at any point from June 14, 2024, through October 12, 2024.12 Since the open negotiation period lasts for 30 days and parties cannot initiate the IDR process until after the negotiation period concludes, this change effectively delayed the ability of parties taking this allowance to initiate disputes, which may have contributed to increases in the number of disputes initiated in Q3 and Q4 of 2024.

Air ambulance disputes peaked in Q1 of 2024, potentially as a result of a backlog of disputes from Q3 and Q4 of 2023. The Departments previously suspended all or part of the IDR process operations for air ambulance disputes between August and mid-December 2023 in response to court decisions.13 Parties of air ambulance disputes that needed to initiate the IDR process during this period were given until March 14, 2024, to initiate the IDR process, which likely contributed to the increase in Q1 air ambulance disputes.14

Who Were the Parties Initiating Disputes?

Although both insurers and providers/facilities may initiate the IDR process if the parties cannot reach an agreement during open negotiation, providers and facilities, as in 2023, were almost always the initiating parties during 2024. As shown in Figure 1, for both categories of OON items or services, providers and facilities initiated more than 99% of the disputes.

Figure 1

. Parties Initiating the Federal IDR Process, 2023-2024

Figure is interactive in the HTML version of this report.

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Source: Departments of Health and Human Services, Labor, and the Treasury, Table 1 in Federal IDR Supplemental Tables, https://www.cms.gov/nosurprises/policies-and-resources/reports ("2023 Reporting Year" and "2024 Reporting Year"). 2023 Q1 and Q2 data as of February 15, 2024; 2023 Q3 and Q4 data as of June 13, 2024. 2024 Q1 and Q2 data as of March 18, 2025; 2024 Q3 and Q4 data as of May 28, 2025.

Notes: IDR = independent dispute resolution; OON = out of network.

For OON emergency/nonemergency services disputes, several provider entities with evidence of private equity affiliations (e.g., Radiology Partners, Team Health, SCP Health, Envision) that were among the top 10 initiating parties in 2023 remain as such in 2024, as shown in Figure 2.15 However, their share of the total percentage of OON emergency/nonemergency disputes initiated decreased from about 67% per quarter in 2023 to 45%-55% per quarter in 2024.

At the same time, the number of third-party representative entities among the top 10 initiating parties—and the proportion of disputes they initiated—increased between 2023 and 2024. In each quarter of 2023, at most 2 of such entities, which appear to generally represent provider entities (at times exclusively in NSA's IDR process),16 are among the top 10 initiating parties, and these 10 parties initiated at most around 5% of OON emergency/nonemergency services disputes collectively. In 2024, each quarter saw at least three third-party representative entities among the top 10 initiating parties, as well as a steady increase in the disputes these entities collectively initiated—from 13% in Q1 to 22% in Q4. One of the third-party representative entities—HaloMD—led the list of top initiating parties in Q4 of 2024 and initiated 18% of all OON emergency/nonemergency services disputes that quarter, as shown in Figure 2.

For OON air ambulance service disputes, the top initiating party in each quarter of 2023 and an entity with evidence of private equity affiliations—Global Medical Response—remained the top initiating party in each quarter of 2024. The proportion of disputes initiated by Global Medical Response increased between 2023 and 2024, from around 50% of disputes in each quarter of 2023 at least 55% disputes in each quarter of 2024. Global Medical Response, together with other top-initiating parties with evidence of private equity affiliations (Air Methods and Apollo MedFlight), initiated 65%-72% of all disputes involving OON air ambulance services in each quarter of 2024.

UnitedHealthcare remained the most frequent non-initiating party for OON emergency/nonemergency service disputes in 2024, according to the Departments' data. As in 2023, UnitedHealthcare participated in around 30% of all disputes in each quarter of the 2024, as shown in Figure 3.

Figure 2

. Percentage of Initiated OON Emergency/Nonemergency Service Disputes by Top Initiating Parties, 2024

Figure is interactive in the HTML version of this report.

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Source: Departments of Health and Human Services, Labor, and the Treasury, Table 8 in Federal IDR Supplemental Tables, https://www.cms.gov/nosurprises/policies-and-resources/reports ("2023 Reporting Year" and "2024 Reporting Year"). 2024 Q1 and Q2 data as of March 18, 2025; 2024 Q3 and Q4 data as of May 28, 2025.

Notes: * refers to initiating parties with private equity affiliations. There is no single authoritative resource that identifies entities affiliated with, or owned by, private equity firms, so private equity affiliation was identified through a compilation of resources that may not be comprehensive. Top initiating parties are those that were a top 10 initiating party in every quarter in 2024. OON = out of network.

Figure 3

. Percentage of Initiated OON Emergency/Nonemergency Service Disputes by Top Noninitiating Parties, 2024

Figure is interactive in the HTML version of this report.

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Source: Departments of Health and Human Services, Labor, and the Treasury, Table 9 in Federal IDR Supplemental Tables, https://www.cms.gov/nosurprises/policies-and-resources/reports ("2023 Reporting Year" and "2024 Reporting Year"). 2024 Q1 and Q2 data as of March 18, 2025; 2024 Q3 and Q4 data as of May 28, 2025.

Notes: * refers to noninitiating parties with private equity affiliations. There is no single authoritative resource that identifies entities affiliated with, or owned by, private equity firms, so private equity affiliation was identified through a compilation of resources that may not be comprehensive. Top noninitiating parties are those that were a top 10 noninitiating party in every quarter in 2024. OON = out of network.

Where Were Disputes Initiated?

As in 2023, disputes involving OON emergency/nonemergency services initiated in 2024 were geographically concentrated in a handful of states. In particular, Texas—where most OON emergency/nonemergency services disputes were initiated in Q2 through Q4 of 2023—remained the state in which most such disputes were initiated in each quarter of 2024. The number of OON emergency/nonemergency services disputes initiated in Texas increased by roughly 12 percentage points relative to 2023 and accounted for over one-third of all disputes involving OON emergency/nonemergency services in 2024 (507,020 disputes, or 36% of disputes). The number of dispute initiations in Texas exceeded the number of initiated disputes involving OON emergency/nonemergency services in the next six states combined (500,020 disputes, or 35% of disputes). In total, the top seven states (Texas, Florida, Arizona, New Jersey, New York, and Tennessee) accounted for over 7 of 10 disputes involving OON emergency/nonemergency services in 2024.17

Disputes involving OON air ambulance services in 2024 were less concentrated geographically than disputes involving OON emergency/nonemergency services but were slightly more concentrated relative to 2023 disputes involving OON air ambulance services. In 2024, 27% of OON air ambulance service disputes were initiated in Texas or Tennessee and the top six states (Texas, Tennessee, California, Arizona, Georgia, and Arkansas) accounted for 50% of all OON air ambulance disputes.18 In 2023, the top two states accounted for 23% of all disputes and the top eight states accounted for 50% of disputes.

Dispute Resolution

How Were Disputes Resolved?

In 2024, IDR entities closed more than 1.37 million disputes, over 1.33 million of which were for OON emergency/nonemergency services and 41,338 of which were for OON air ambulance services. This total is almost 4½ times greater than the total number of disputes closed in 2023 (311,863) and over 25 times greater than the total number of disputes closed in 2022 (54,821).19 The Departments attribute some of this increase to IDR entities scaling up their operations.20

As shown in Figure 4, over three-fourths of closed disputes in 2024 resulted in payment determinations (nearly 1.048 million), which is a roughly 10-percentage-point increase over 2023. The number of payment determinations increased each quarter in 2024, and the number of payment determinations in Q4 of 2024 was more than 2½ times greater than the number of payment determinations in Q1 of 2024.

Just under one-fifth of the closed disputes in 2024 (262,441, or approximately 19%) were found ineligible for the federal IDR process; this rate is similar to 2023 levels (approximately 22%). This ineligibility rate may be stabilizing as more parties gain familiarity with the IDR process. The approximately one-in-five ineligible rate speaks to the complexity that parties face when determining whether a dispute is eligible for the IDR process. A dispute can be found ineligible for various reasons, including because a state law or all-payer model agreement should apply instead of the federal methodology, the initiating party did not comply with IDR process timelines, the parties did not complete the open negotiation period, and/or the initiating party did not correctly batch or bundle the claims. (Batched claims refer to situations in which multiple qualified services are considered jointly as part of one IDR determination; bundled claims refer to situations in which a provider or facility bills for multiple items or services under a single service code.)

Figure 4

. Federal IDR Process Payment Determination Outcomes, 2023-2024

Figure is interactive in the HTML version of this report.

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Source: Departments of Health and Human Services, Labor, and the Treasury, Table 5 in Federal IDR Supplemental Tables, https://www.cms.gov/nosurprises/policies-and-resources/reports ("2023 Reporting Year" and "2024 Reporting Year"). 2023 Q1 and Q2 data as of February 15, 2024; 2023 Q3 and Q4 data as of June 13, 2024. 2024 Q1 and Q2 data as of March 18, 2025; 2024 Q3 and Q4 data as of May 28, 2025.

Notes: IDR = independent dispute resolution; OON = out of network. "Other" indicates disputes that were withdrawn by disputing parties, closed due to outside settlement between the disputing parties, or closed for administrative reasons. A dispute can be found ineligible for various reasons, including because a state law or all-payer model agreement should apply, the initiating party did not comply with IDR process timelines, the parties did not complete the open negotiation period, and/or the initiating party did not correctly batch or bundle the claims.

How Long Did It Take for IDR Entities to Make Payment Determinations?

The statute and implementing regulations generally required an IDR entity to issue a determination to the parties and close a dispute within 33 business days of the initial selection of the IDR entity.21 A majority of payment determinations in 2024 were made outside the 33-business-day period, though certain improvements were observed as the year went on. For OON emergency/nonemergency service disputes, the median number of days to determination slightly decreased in Q4 of 2024 relative to Q1-Q3 (54 business days to determination in Q4 relative to a range of 67-74 business days to determination in Q1-Q3). There was also an improvement in quarter-over-quarter increases in the percentage of disputes determined within the 33-business day window in Q4 of 2024 (16% in Q1, 24% in Q2, 29% in Q3, and 35% in Q4). These improvements are notable given that the number of determinations also increased each quarter in 2024. In contrast, OON air ambulance disputes saw quarter-over-quarter increases in the median number of days to determination from Q1 to Q4 (34 business days in Q1 and 93 business days in Q4) and decreases in the percentage of disputes determined within the 33-business-day window in 2024 (49% in Q1 and 32% in Q4).

Determinations made outside of the 33-business-day period do not necessarily indicate that the IDR entities did not meet appropriate deadlines. Residual effects of pauses in the IDR process in the second half of 2023, for example, appear to have impacted early 2024 payment determination statistics. In response to the reopening of the IDR portal to all dispute types in December 2023, the Departments provided extensions to various components of the IDR process that were available through March 14, 2024.22 Specifically, parties were provided up to 10 business days to jointly select an IDR entity, IDR entities could provide parties with an additional 10 business days to submit an offer, and IDR entities could provide parties with additional time to respond to its request for information. These timeline extensions would have contributed to increased determination timelines in early 2024.

The Departments have stated that the primary cause of determination delays is the complexity involved in determining dispute eligibility.23 Specifically, the Departments identified two factors that can complicate the eligibility determination: (1) whether a state law or all-payer model agreement should apply instead of the federal IDR process and (2) whether disputes involving multiple items and services have been appropriately batched or bundled.24 Previous CRS analysis of 2023 data indicated that these challenges largely affected all dispute types similarly in that year;25 in 2024, by contrast, single and non-air ambulance bundled disputes frequently were resolved more quickly than batched disputes, particularly in Q4, where the median number of days to resolve OON emergency/nonemergency batched disputes (98 days) was over two times the median number of days it took to resolve OON emergency/nonemergency single disputes (46 days) and bundled disputes (39 days) (Table 1).26 The median number of days to resolve single and batched OON air ambulance disputes increased throughout 2024, and the median number of days to resolve bundled disputes was particularly elevated in Q1 (342 days) and Q3 (299.5 days). (Bundled OON air ambulance disputes were uncommon, representing 0.22% of air ambulance disputes in all of 2024.) The Departments proposed a rule in November 2023 that sought to further improve the eligibility determination process, but this rule had not been finalized as of the publication date of this report.27 In 2025, the Departments certified additional IDR entities and updated the IDR initiation form to facilitate quicker dispute eligibility determinations.

Table 1. Median Number of Business Days to Determination for Disputes, by Quarter and Dispute Type, 2024

Q1

Q2

Q3

Q4

Batched

Bundled

Single

Batched

Bundled

Single

Batched

Bundled

Single

Batched

Bundled

Single

Median Number of Business Days to Resolve OON Emergency/
Nonemergency Disputes

127

75

69

61

37

73

100

44

67

98

39

46

Median Number of Business Days to Resolve OON Air Ambulance Dispute

34

342

34

58

83

37

55

299.5

56

106

79

87

Source: CRS analysis of the Departments of Health and Human Services, Labor, and the Treasury, "Federal IDR PUF for 2024, Q1"; "Federal IDR PUF for 2024, Q2"; "Federal IDR PUF for 2024, Q3"; and "Federal IDR PUF for 2024, Q4," https://www.cms.gov/nosurprises/policies-and-resources/reports ("2024 Reporting Year"). Q1 and Q2 data as of March 18, 2025; Q3 and Q4 data as of May 28, 2025.

Notes: IDR = independent dispute resolution; OON = out of network; PUF = public use file. Batched disputes are disputes in which multiple qualified services are considered jointly as part of one IDR determination. Bundled disputes are disputes in which a provider or facility billed for multiple items or services under a single service code.

Who Were the Prevailing Parties in Disputes, and How Do the Payment Determinations Compare with the Qualifying Payment Amount?

For disputes that resulted in payment determinations during 2024, Figure 5 illustrates the determination outcome. Providers and facilities were the prevailing party—that is, had their offers selected—in approximately 85% of OON emergency/nonemergency service and OON air ambulance service determinations during 2024. Insurers, by contrast, were the prevailing party in approximately 15% of determinations. A small number of disputes resulted in split decisions, which refer to batched disputes where each party prevailed in an equal number of batched dispute determinations.

In 2024, providers and facilities improved upon their initial success with the IDR process for OON emergency/nonemergency service determinations relative to 2023. The percentage of claims in which providers and facilities were the prevailing party for OON emergency/nonemergency service determinations increased from 80% in 2023 to approximately 85% in 2024. Much of this 2024 increase was attributable to the amount of default determinations in favor of providers/facilities, particularly in Q4 of 2024. In default determinations, only one party to the dispute submitted an offer and paid fees; thus, it prevailed by default. In both 2023 and 2024, providers and facilities won about 85% of non-default determination disputes. With respect to default determinations, however, providers and facilities were only slightly more likely than insurers to prevail by default in 2023, prevailing in 57% of 2023 default determinations. In contrast, in 2024, providers and facilities prevailed in 83% of default determinations. In Q4 of 2024, 26% of disputes were resolved through a default and approximately 90% of default disputes were decided in favor of providers and facilities. This was the highest rate of default determinations in a quarter in 2023 or 2024 (previous rates had ranged from 11% to 22% of quarterly determinations) and the highest provider and facility quarterly success rate among default determinations, which previously ranged from 47% to 82%. This shift indicates lower insurer engagement with the IDR process in 2024—and in particular, in Q4 of 2024—relative to 2023.

Air ambulance providers generally maintained their success with the IDR process for OON air ambulance service disputes from 2023 to 2024. Air ambulance providers were the prevailing party in 85% of disputes in 2023 and 87% of disputes in 2024.

Figure 5

. Prevailing Party in IDR Payment Determinations, 2023-2024

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Source: Departments of Health and Human Services, Labor, and the Treasury, Table 12 in Federal IDR Supplemental Tables, https://www.cms.gov/nosurprises/policies-and-resources/reports ("2023 Reporting Year" and "2024 Reporting Year"). 2023 Q1 and Q2 data as of February 15, 2024; 2023 Q3 and Q4 data as of June 13, 2024. 2024 Q1 and Q2 data as of March 18, 2025; 2024 Q3 and Q4 data as of May 28, 2025.

Notes: IDR = independent dispute resolution; OON = out of network.

In terms of the offer amounts selected, payment determinations were more likely to be above the QPA at issue (i.e., greater than, generally, the 2019 median in-network rate for the item or service at issue, indexed for inflation) in 2024 than in 2023. Approximately 85% of the payment determinations reached in 2024 resulted in the selection of a prevailing offer greater than the QPA, as compared with approximately 80% in 2023. The Departments have observed that insurers often benchmark their offers to the QPA, and data indicate that at least half of insurers' offers were at or below the QPA in every quarter since 2023 except in Q3 of 2024, as shown in Figure 6.28

Figure 6

. Insurer Offers for OON Emergency/Nonemergency Service Disputes as a Percentage of QPA, 2023-2024

Figure is interactive in the HTML version of this report.

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Source: CRS analysis of the Departments of Health and Human Services, Labor, and the Treasury, "Federal IDR PUF," https://www.cms.gov/nosurprises/policies-and-resources/reports ("2023 Reporting Year" and "2024 Reporting Year"). 2023 Q1 and Q2 data as of February 15, 2024. 2023 Q3 and Q4 data as of June 13, 2024. 2024 Q1 and Q2 data as of March 18, 2025. 2024 Q3 and Q4 data as of May 28, 2025.

Notes: PUF = public use file; QPA = qualifying payment amount (i.e., generally, the 2019 median in-network rate for the item or service at issue, indexed for inflation). CRS analysis is at the dispute line-item level and excludes instances where the QPA was not reported or was not available.

Figure 7 illustrates, for each quarter, the medical specialties involved in over 5,000 payment determinations in a single quarter and shows the median prevailing offer for the disputes involving that specialty as a percentage of the QPA. The Departments' data show that in 2024, emergency department services were the subject of the greatest number of payment determinations (roughly 45% of all determinations), and the median prevailing offer in those determinations was relatively stable during the year, ranging from roughly 2½ to 3 times QPA in each quarter. Radiology services, as in 2023, were subject to the second-greatest number of payment determinations in 2024 (roughly 20% of all determinations); the median prevailing offer in those determinations increased from Q1 of 2023 (nearly three times the QPA) through Q1 of 2024 (over six times the QPA) but decreased gradually through the remainder of 2024 to approximately five times the QPA by Q4 of 2024. In 2024, no other specialty accounted for more than 10% of determinations.

The Departments' data show that (1) surgery and (2) neurology and neuromuscular procedure determinations together accounted for a smaller number of determinations in 2024 (combined, 16% of all determinations) relative to emergency department or radiology services. The median prevailing offer for both of these specialty determinations, however, has increased significantly since 2023. According to the same data, the median prevailing offer for disputes involving surgery increased from around 3 times the QPA in Q1 of 2023 to nearly 13 times the QPA in Q4 of 2024; for disputes involving neurology and neuromuscular procedures, the median prevailing offer increased from over 3 times the QPA in Q1 of 2023 to almost 17 times the QPA in Q4 of 2024.

Contributing to this growth in the median prevailing offers appear to be increases in the percentage of determinations for both (1) surgery procedures and (2) neurology and neuromuscular procedures with a prevailing offer at or above 3,000% of QPA and, in particular, determinations above 10,000% of QPA.29 In the first half of 2024, 20% of surgery and 19% neurology and neuromuscular procedure determinations were at least 3,000% of QPA. In the second half of 2024, the Departments' data show that 29% of prevailing offers for surgery determinations and 36% of prevailing offers for neurology and neuromuscular procedure determinations exceeded this 3,000% of QPA threshold. Between the first half and the second half of 2024, determinations at or above 10,000% of QPA increased from 5% to 13% for neurology and neuromuscular procedure determinations and from 5% to 9% for surgery determinations.

The Departments acknowledged that smaller dollar items had higher prevailing offers expressed as a percentage of QPA, because smaller dollar differences can result in larger percentage changes. This correlation may be more pertinent to neurology and neuromuscular procedure determinations, as the median QPA among these types of non-default determinations where the prevailing offer was above 3,000% in 2024 (and where the prevailing offer and QPA were reported) was $76. Among surgical non-default determinations where the prevailing offer was above 3,000% in 2024 (and where the prevailing offer and QPA were reported), the median QPA was $213.

Figure 7

. Median Prevailing Offer of IDR Payment Determinations as a Percentage of QPA for Each Specialty, 2023-2024

Figure is interactive in the HTML version of this report.

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Source: Departments of Health and Human Services, Labor, and the Treasury, Table 14 in Federal IDR Supplemental Tables, https://www.cms.gov/nosurprises/policies-and-resources/reports ("2023 Reporting Year" and "2024 Reporting Year"). 2023 Q1 and Q2 data as of February 15, 2024; 2023 Q3 and Q4 data as of June 13, 2024. 2024 Q1 and Q2 data as of March 18, 2025; 2024 Q3 and Q4 data as of May 28, 2025.

Notes: Chart includes only specialties that had more than 5,000 determinations in a single quarter. QPA = qualifying payment amount (i.e., generally, the 2019 median in-network rate for the item or service at issue, indexed for inflation). Analysis is at the dispute line-item level and excludes instances where the QPA was not reported or was not available.

How Much Did Parties Pay in Fees?

To participate in the IDR process, parties must pay two fees: both parties must pay an administrative fee that goes to the federal government for the operation of the IDR process, and, generally, the party whose offer is not chosen must pay a fee to the IDR entity.30

For most of 2024, the administrative fee was $115 per party, an amount set by the Departments through rulemaking. This amount, as required by the NSA, reflects the Departments' estimate regarding their total cost for carrying out the IDR process.31

Each IDR entity can determine its own fee amount, but generally these fees fall within a range determined annually by the Departments.32 For most of 2024, the fee range for a single determination was $200-$840; for batched determinations, the fee range was $268-$1,173.33 For batched disputes exceeding 25 dispute line items, IDR entities also were allowed to set a fixed fee between $75 and $250 for each additional increment of 25 dispute line items.

In total, parties paid $718 million in fees in 2024, of which $559 million was paid to IDR entities and $159 million was paid the Departments as administrative fees.34

Observations and Future Considerations

The year 2024 marked the first year in which the IDR process was operational throughout the year. Relative to 2023, 2024 saw significant increases in the use of the IDR process by providers and facilities, a large increase in the number of determinations made, improvements in the number of OON emergency/nonemergency service dispute determinations made within 33 business days (though a majority of determinations were still made outside of that window), and continued notable increases in payment determination amounts in certain medical specialties.

Independent Dispute Resolution Process Utilization

The Departments' data show that utilization of the IDR process has grown every year since the process became operational in 2022. In 2024, the total number of disputes initiated was more than twice the total number of disputes initiated in 2023 and more than seven times the total number of disputes initiated in 2022. Providers and facilities—which continued to improve upon their success rate in 2024, with their offers selected in approximately 85% of disputes involving OON emergency/nonemergency services compared with 80% in 2023—also continued to overwhelmingly be the party initiating disputes. Although providers with evidence of private equity affiliation continue to be heavy utilizers of the IDR process in 2024—top initiating parties with private equity affiliation initiated around 45%-55% of disputes involving OON emergency/nonemergency services in each quarter—the proportion of disputes initiated by such providers decreased relative to 2023. Meanwhile, 2024 saw a significant increase in the proportion of disputes involving OON emergency/nonemergency services initiated by third-party entities representing providers. Researchers have indicated that these third-party entities may make it easier for smaller providers to utilize the IDR process by taking on the administrative burden of managing disputes.35 At the same time, several insurers have filed suit against one third-party representative—HaloMD, the top initiating party in Q4 of 2024—alleging that the representative engaged in a fraudulent scheme to flood the IDR process with ineligible and inflated disputes.36 Future analysis may track the pending lawsuits and consider the extent to which third-party representatives contributed to growth in IDR process utilization.

The Departments' 2024 data also indicate signs of disengagement from the IDR process by insurers. The data indicate a higher proportion of default determinations in favor of providers and facilities relative to 2023; in these determinations, providers and facilities prevailed by default because they were the only party to have paid fees and submitted an offer. Future analysis may explore any patterns among the default determinations. Such analysis may consider, for instance, any changes in the pattern of default determinations following the U.S. Court of Appeals of the Fifth Circuit's (Fifth Circuit) June 2025 decision in Guardian Flight, L.L.C. v. Health Care Service Corp.37 In Guardian Flight, the court affirmed the district court's order holding that the NSA does not provide a cause of action to providers that prevail in IDR disputes to sue insurers to enforce and obtain the payment determination amounts.38 In the court's view, the NSA's timely payment requirement following a payment determination is enforceable only through administrative penalties.39 As a practical matter, this construction means that a prevailing party in the IDR process that has not received timely payment of the payment determination amount cannot directly recover such payment by filing a civil action. Instead, the primary recourse for such a prevailing party is to submit a complaint with CMS;40 the Departments, in turn, have discretion to determine whether to initiate an enforcement proceeding against the subject of the complaint.41 Although other lower courts have not adopted the construction in Guardian Flight,42 which is binding only in the Fifth Circuit, future analysis may consider whether Guardian Flight—which limits the ability of a provider that is a prevailing party to enforce an IDR award and obtain payment against an insurer—has impacted insurers' participation in the IDR process at the outset.

Payment Determinations

In 2024, emergency department services and radiology continued to be, as they were in the prior year, the top two medical specialties subject to disputes involving OON emergency/nonemergency services, together comprising nearly two-thirds of all such disputes. The median payment determination amounts related to these specialties were, across 2023 and 2024, stable for emergency department services (ranging from just over two times to three times the QPA) and for radiology services (between nearly three times the QPA and just over six times the QPA).

In contrast, the median payment determination amounts for disputes involving two other specialties, (1) surgery and (2) neurology and neuromuscular procedures, increased significantly since 2023. Preliminary analysis shows that growth in the median payment amounts in the second half of 2024 appears to be due to increases in the percentage of determinations for both specialties that had a prevailing offer over 30 times the QPA and, in particular, determinations above 100 times of QPA. Continued large increases in payment determination outcomes would not affect consumer cost sharing for such care, because cost sharing in OON surprise billing situations is based on the QPA,43 but could create upward pressure on other in-network negotiated rates and, subsequently, on plan premiums.

One threshold question raised by this payment determinations analysis—which generally uses QPA as a benchmark for interpreting IDR outcomes—is whether the QPA is the appropriate benchmark. Providers and insurers have indicated differing opinions on the QPA. For example, providers have contested that certain implementing methodological features artificially lower the QPA,44 while insurers have indicated that the QPA represents the market rate for services.45 More research of the QPA relative to claims data and/or in-network rates, for example, could help with interpretations of IDR outcomes (including with respect to specific specialties) relative to a QPA benchmark. Future analysis also may further explore the payment determination amount increases involving these specialties. For example, additional analysis may continue to monitor whether there is a pattern related to their Current Procedure Terminology (CPT) codes,46 geographies, or other features. Furthermore, the extent to which the median prevailing offer remains elevated above QPAs may warrant analysis that looks at whether such elevated rates correlate with disproportionate increases in the number of service disputes for these specialties relative to other specialties. To the extent that elevated rates are observed in more medical specialties, such observation also may warrant analysis that considers potential implications for provider network participation.

Independent Dispute Resolution Process Operations

In terms of IDR process operation, the Departments' 2024 data show that payment determinations continued to frequently take longer than the statutorily designated time frame. This may have been attributable to both the increased volumes of disputes initiated and the residual effects of periods of IDR process suspension in 2023. At the same time, IDR entities ramped up their processes to resolve more than 4½ times more disputes in 2024 than in 2023. That the rates of initiation and determination generally increased quarter over quarter in 2024 implies that utilization of the IDR process and greater efficiencies in IDR determinations by IDR entities may continue into 2025. The certification of additional IDR entities in 2025 and an updated IDR initiation form may further contribute to improved efficiencies in 2025. Finally, should the Departments finalize their 2023 proposed rule, which addresses many aspects of IDR operation, including revised batching rules and the administrative fee structure and amounts, that may further affect IDR process operations.47 Continued observation and analysis of the 2025 data could consider the extent to which these developments affected the volume of dispute determination and the time to determination.


Mari Y. Lee, Visual Information Specialist, helped produce the figures within this product.

Footnotes

1.

For more information on surprise billing requirements included in the No Surprises Act (NSA; part of the Consolidated Appropriations Act, 2021 [P.L. 116-260]), see CRS Report R46856, Surprise Billing in Private Health Insurance: Overview of Federal Consumer Protections and Payment for Out-of-Network Services.

2.

For ease of reading, this product uses the term insurer to refer collectively to both health plans and issuers.

3.

42 U.S.C. §300gg-111(c). For more information on the federal independent dispute resolution (IDR) process, see CRS In Focus IF12073, Surprise Billing: Independent Dispute Resolution Process.

4.

See Katie Keith, "Health Care Providers Fight Arbitration Rule in No Surprises Act," Commonwealth Fund, March 17, 2022, https://www.commonwealthfund.org/blog/2022/health-care-providers-fight-arbitration-rule-no-surprises-act.

5.

42 U.S.C. §300gg-111(c)(5)(C). This methodology does not apply in all situations. If a state has its own surprise billing law that pertains to a given plan type, provider type, or service, the state law methodology applies. In addition, if a state has an all-payer model agreement, the amount designated under the agreement applies. 42 U.S.C. §300gg-111(a)(3)(K).

6.

Disputes initiated in Q2 of 2022 include disputes that would have been eligible for the IDR process beginning January 1, 2022. Department of Health and Human Services (HHS), Department of Labor, and Department of the Treasury, Initial Report on the Independent Dispute Resolution (IDR) Process April 15-September 30, 2022, p.7, https://www.cms.gov/files/document/initial-report-idr-april-15-september-30-2022.pdf (hereinafter HHS, Department of Labor, and Department of the Treasury, Initial Report on the IDR Process).

7.

See Centers for Medicare & Medicaid Services (CMS), Notices, August 25, 2023, https://www.cms.gov/nosurprises/notices (see "Notices from 2023"). Relevant court decisions include, for instance, Tex. Med. Assoc. v. U.S. Dep't of Health & Human Servs., 654 F. Supp. 3d 575 (E.D. Tex. 2023) and Tex. Med. Assoc. v. U.S. Dep't of Health & Human Servs., No. 6:22-cv-450, 2023 WL 5489028 (E.D. Tex. Aug. 24, 2023). For more information on the legal challenges to the No Surprises Act, see CRS Legal Sidebar LSB11036, Overview of Selected No Surprises Act Litigation.

8.

The NSA directs HHS, the Department of Labor, and the Department of the Treasury to publish, on a quarterly basis, information about the implementation of the IDR process. This information includes, among other things, the total number of disputes initiated; the sizes and types of organizations that were party to a dispute; and details of each payment determination, including a description of the items or services disputed, the identities of the disputing parties, the payment offers submitted by each party, and the final payment determination. 42 U.S.C. §300gg-111(c)(7).

9.

In general, this report categorizes data for the types of surprise billing situations eligible for the IDR process as (1) OON emergency services and OON nonemergency services provided during a visit at an in-network facility and (2) OON air ambulance services. This approach, which generally combines the data for OON emergency services and OON nonemergency services, is consistent with how CMS presents the data in public-use files and supplemental tables. Given this data structure and that IDR disputes predominantly consist of OON emergency and nonemergency services, certain graphics in this report do not include data reflecting OON air ambulance services. For more information on CRS's previous analysis, see CRS Report R48058, No Surprises Act Independent Dispute Resolution (IDR) Process Data Analysis for the First Half of 2023, and CRS Report R48359, No Surprises Act (NSA) Independent Dispute Resolution (IDR) Process Data Analysis for 2023.

10.

Of the 2023 total, 657,040 disputes involved OON emergency/nonemergency services and 22,116 disputes involved OON air ambulance services. Of the 2022 total, 189,977 were disputes involving OON emergency/nonemergency services and 10,135 were disputes involving OON air ambulance services. CRS Report R48359, No Surprises Act (NSA) Independent Dispute Resolution (IDR) Process Data Analysis for 2023; and HHS, Department of Labor, and Department of the Treasury, Partial Report on the Independent Dispute Resolution (IDR) Process October 1-December 31, 2022, p. 8, https://www.cms.gov/files/document/partial-report-idr-process-octoberdecember-2022.pdf (hereinafter HHS, Department of Labor, and Department of the Treasury, Partial Report on the IDR Process), respectively.

11.

For more information about the Change Healthcare cybersecurity incident, see CRS Insight IN12330, The Change Healthcare Cyberattack and Response Considerations for Policymakers, by Chris Jaikaran.

12.

This flexibility applied to items and services furnished on or after January 1, 2024. CMS, Notices, June 14, 2024, https://www.cms.gov/nosurprises/notices (see "Notices from 2024").

13.

The suspension also affected OON emergency or nonemergency disputes, but to a lesser extent. See CMS, Notices, August 25, 2023, https://www.cms.gov/nosurprises/notices (see "Notices from 2023"). For more information on the legal challenges to the No Surprises Act, see CRS Legal Sidebar LSB11036, Overview of Selected No Surprises Act Litigation.

14.

CMS, Notices, December 21, 2023, https://www.cms.gov/nosurprises/notices (see "Notices from 2023").

15.

Private equity refers to a type of private fund that pools money from certain types of investors and invests the money on behalf of the fund. There is no single authoritative resource that identifies entities affiliated with, or owned by, private equity firms, so private equity affiliation was identified through a compilation of resources that may not be comprehensive. In this context, private equity affiliation indicates private equity ownership or investment. For more information about private equity and the concerns some observers have raised regarding the involvement of private equity in health care at large, see "Industry-Specific Debates" in CRS Report R47053, Private Equity and Capital Markets Policy, by Eva Su.

16.

For example, see, HaloMD, "About Us," https://halomd.com/about-us/, and Gottlieb & Greenspan, "Services," https://gottliebandgreenspan.com/healthcare-reimbursement-services/.

17.

HHS, Department of Labor, and Department of the Treasury, Table 7 in Federal IDR Supplemental Tables for 2024, Q1; Table 7 in Federal IDR Supplemental Tables for 2024, Q2; Table 7 in Federal IDR Supplemental Tables for 2024, Q3; and Table 7 in Federal IDR Supplemental Tables for 2024, Q4, https://www.cms.gov/nosurprises/policies-and-resources/reports ("2024 Reporting Year"). States are listed in descending order of initiated disputes involving OON emergency/nonemergency services.

18.

States are listed in descending order of initiated disputes involving OON air ambulance services.

19.

HHS, Department of Labor, and Department of the Treasury, Initial Report on the IDR Process, p. 8; and HHS, Department of Labor, and Department of the Treasury, Partial Report on the IDR Process, pp. 8-9.

20.

HHS, Department of Labor, and Department of the Treasury, Supplemental Background on Federal Independent Dispute Resolution Public Use Files July 1, 2024-December 31, 2024, p. 2, https://www.cms.gov/files/document/federal-idr-supplemental-background-2024-q3-2024-q4.pdf (hereinafter HHS, Department of Labor, and Department of the Treasury, Supplemental Background, July 1, 2024-December 31, 2024).

21.

42 U.S.C. §300gg-111(c)(5), 45 C.F.R. §149.510(c)(1)(v), and 45 C.F.R. §149.510(c)(4)(ii). See also CMS, Notices (November 22, 2024; July 19, 2024; December 21, 2023) https://www.cms.gov/nosurprises/notices (noting that the Departments of Health and Human Services, Labor, and the Treasury have previously granted extensions related to IDR process suspensions, natural disasters, and large-scale software outage or cybersecurity incidents).

22.

CMS, Notices, December 21, 2023, https://www.cms.gov/nosurprises/notices (see "Notices from 2023").

23.

HHS, Department of Labor, and Department of the Treasury, Supplemental Background, July 1, 2024-December 31, 2024, p. 3.

24.

HHS, Department of Labor, and Department of the Treasury, Initial Report on the IDR Process, p. 9.

25.

For more information, see CRS Report R48359, No Surprises Act (NSA) Independent Dispute Resolution (IDR) Process Data Analysis for 2023; Tex. Med. Assoc. v. U.S. Dep't of Health & Human Servs., No. 6:23-cv-59, 2023 WL 4977746 (E.D. Tex. Aug. 3, 2023); Tex. Med. Assoc. v. U.S. Dep't of Health & Human Servs., No. 6:22-cv-450, 2023 WL 5489028 (E.D. Tex. Aug. 24, 2023).

26.

2024 determinations may have seen residual effects from the suspension in certain payment determinations from August 3, 2023, through December 14, 2023. For more information, see CRS Report R48359, No Surprises Act (NSA) Independent Dispute Resolution (IDR) Process Data Analysis for 2023.

27.

Office of Personnel Management; Department of the Treasury, Internal Revenue Service; Department of Labor, Employee Benefits Security Administration; HHS, CMS, "Federal Independent Dispute Resolution Operations," 88 Federal Register 75744, November 3, 2023 (hereinafter 88 Federal Register 75744).

28.

HHS, Department of Labor, and Department of the Treasury, Supplemental Background, July 1, 2024-December 31, 2024, p. 4.

29.

CRS analysis was conducted at the dispute line-item level and excluded (1) instances where the prevailing offer as a percentage of QPA was not reported or was not available and (2) default determinations (i.e., determinations where one party failed to submit an offer or pay the fees, resulting in the selection of the other party's offer). HHS, Department of Labor, and Department of the Treasury, Supplemental Background, July 1, 2024-December 31, 2024, p. 4.

30.

After the IDR process is initiated but before there is a determination, insurers and providers may continue to negotiate a payment amount. If the parties reach an agreement through negotiation during this period, the agreed-upon rate is treated as the final payment rate. The parties would split the IDR entity fee unless the parties agreed otherwise.

31.

42 U.S.C. §300gg-111(c)(8)(B); 45 C.F.R. §149.510(d)(2)(ii); Department of the Treasury, Department of Labor, HHS, "Federal Independent Dispute Resolution (IDR) Process Administrative Fee and Certified IDR Entity Fee Ranges," 88 Federal Register 88494, December 21, 2023 (hereinafter 88 Federal Register 88494).

32.

45 C.F.R. §149.510(e)(2)(vii).

33.

88 Federal Register 88494.

34.

Departments of Health and Human Services, Labor, and the Treasury, Table 6 in Federal IDR Supplemental Tables for 2024, Q1; and Table 6 in Federal IDR Supplemental Tables for 2024, Q2; Table 6 in Federal IDR Supplemental Tables for 2024, Q3; and Table 6 in Federal IDR Supplemental Tables for 2024, Q4; https://www.cms.gov/nosurprises/policies-and-resources/reports ("2024 Reporting Year").

35.

Jack Hoadley et al., "Independent Dispute Resolution Process 2024 Data: High Volume, More Provider Wins," Health Affairs Forefront, June 11, 2025, at https://www.healthaffairs.org/content/forefront/independent-dispute-resolution-process-2024-data-high-volume-more-provider-wins.

36.

See, for instance, Community Ins. Co. v. HaloMD, LLC, No. 1:25-CV-388, Dkt. 1 (S.D. Ohio, filed June 10, 2025); Blue Cross Blue Shield Healthcare Plan of Georgia, Inc. v. HaloMD, Inc., No. 1:25-CV-2919, Dkt. 1 (N.D. Ga., filed May 27, 2025).

37.

140 F.4th 271 (2025).

38.

140 F.4th 271 at 275.

39.

140 F.4th 271 at 277.

40.

See CMS, "Providers: Submit a Billing Complaint," https://www.cms.gov/nosurprises/policies-and-resources/providers-submit-a-billing-complaint.

41.

42 U.S.C. §300gg-22(b).

42.

See, for instance, GPS of New Jersey M.D., P.C. v. Horizon Blue Cross & Blue Shield, No. 22-cv-6614, 2023 WL 5815821 (D.N.J. Sept. 8, 2023) (holding that the NSA "gives the court the authority" to enforce the IDR award).

43.

42 U.S.C. §300gg-111(a)(1)(C)(iii).

44.

For example, providers have challenged the inclusion of rates for services with providers regardless of whether the provider actually provides that service. See Tex. Med. Assoc. v. U.S. Dep't of Health & Human Servs., 120 F.40 494, 504-505 (5th Cir. 2024), reh'g en banc granted, vacated by 138 F. 4th 961 (5th Cir. 2025); CRS Legal Sidebar LSB11036, Overview of Selected No Surprises Act Litigation.

45.

Petra W. Rasmussen, Erin L. Duffy, and Isha Yardi, et al., The Implications of the No Surprises Act on Contract Dynamics, Negotiations, and Finances, RAND Health Care, December 2024, p. 17, https://aspe.hhs.gov/sites/default/files/documents/754f61834289cdd719b542035ee36eba/PRA-1820-9.pdf.

46.

Current Procedure Terminology (CPT) codes are uniform numerical codes maintained by the American Medical Association used to identify medical services and procedures. American Medical Association, CPT Codes, https://www.ama-assn.org/topics/cpt-codes.

47.

88 Federal Register 75744.