The Apellica External Review Index.
How often a U.S. state-licensed Independent Review Organization overturns an insurance denial ranges from 17.0% in West Virginia to 80.0% in Connecticut. Most states do not even publish the number. This is the first comprehensive 2026 public-record dataset, with every cell anchored to a verifiable government source.
Released by Apellica under CC-BY-4.0. Reuse it. Cite it. Improve it. Open an issue or send corrections to editorial@apellica.com.
A working map of the data the system does not publish.
The Affordable Care Act gave every American with a fully-insured plan the right to ask a state-licensed Independent Review Organization to re-decide a denial after the insurer's own internal appeal process is exhausted. The reviewer is independent. The decision is binding on the insurer.
How often that reviewer sides with the patient is wildly different depending on which state you live in. And in most states, the regulator does not publicly publish the number at all.
This dataset assembles what each state's Department of Insurance, legislative report, or CMS publication says about their external-review program — in one place, with every number anchored to a verifiable public-record URL. Empty cells are deliberately empty when the underlying state has not published the number. We do not extrapolate.
The single largest finding of the exercise is that transparency itself is the lottery. 42 of 56 jurisdictions do not publish discoverable current external-review statistics. The patient who needs the data to decide whether to appeal has no way to get it.
External-review reversal rate by jurisdiction.
| Jurisdiction | Year | Reversal rate | Cases | Overturned | System | Regulator |
|---|---|---|---|---|---|---|
| Connecticut CT | 2024 | 80.0% High reversal | — | — | state-run | Connecticut Insurance Department / Office of the Healthcare AdvocateNotesHealthcare Advocate office reports denials resolved/overturned in patient's favor ~80% of cases. Counts include both formal IRO reversals and pre-decision insurer concessions after advocate involvement. CT total denial rate among largest insurers was 14% in 2024. |
| California CA | 2024 | 72.7% High reversal | — | — | state-run | California Department of Managed Health Care (DMHC)NotesHeadline: ~73% of IMR cases end with enrollee receiving requested service (full+partial overturn by IMRO + plan reversals during review). Of cases reaching final IMRO determination, overturn rate of treatment-denial decisions was 12.7% in 2024 (up from 10.2% in 2023). Full open-data trend file: https://data.chhs.ca.gov/dataset/independent-medical-review-imr-determinations-trend |
| Maryland MD | 2024 | 66.8% High reversal | — | — | state-run | Maryland Insurance Administration (MIA)NotesMIA reversed or modified the carrier's grievance decision 66.8% of the time in 2024, per MIA's 2024 Health Care Appeals and Grievance Law Report. Down 2.9 pts from prior year. Note: this is MIA's complaint-handling reversal rate, broader than IRO-only external review. Source PDF identified. |
| North Carolina NC | 2024 | 54.3% High reversal | 282 | 153 | state-run | North Carolina Department of Insurance (Smart NC)NotesSmart NC received 282 external review requests through November 2024 and overturned 153 (~53%). Per Smart NC and NBC News reporting (2025). Annual report: https://www.ncleg.gov/Files/Library/agency/doi13339.pdf |
| Kansas KS | 2024 | 54.0% High reversal | — | — | state-run | Kansas Insurance DepartmentNotes~54% overturn rate cited by NBC News (2025) attributing to Kansas Department of Insurance covering data since 2018. Cumulative period rate; not single-year. Department publishes Independent Medical Review program at: https://insurance.ks.gov/documents/department/publications/independent-medical-review.pdf |
| Pennsylvania PA | 2025 | 48.4% Moderate | 1,353 | 655 | state-run | Pennsylvania Insurance Department (PID)NotesPA Independent External Review Program (launched 2024-01) referred 1353 eligible cases to IROs since inception through 2025; 655 overturned (~48%). First-year (2024) rate was 50.1%. Program is one of newest state-run replacements for HHS-administered process. |
| Colorado CO | 2024 | 44.0% Moderate | — | — | state-run | Colorado Division of Insurance (DORA)Notes~44% overturn rate cited by Division (per NBC News 2025 coverage attributing to DORA). Statistical report exists but item-level external-review tables not extracted; flag as secondary citation. |
| Minnesota MN | 2024 | 43.0% Moderate | — | — | state-run | Minnesota Department of CommerceNotes43% of external reviews resulted in coverage denials being overturned in 2024, per Department of Commerce (cited via KSTP News). Filing fee dropped 2024-08-01 to increase access. |
| South Carolina SC | 2024 | 43.0% Moderate | — | — | state-run | South Carolina Department of InsuranceNotes~43% of cases reversed in 2024 per NBC News attribution to SCDOI. SC DOI does not publish dedicated annual external-review report online; flag as secondary citation. |
| Massachusetts MA | 2023 | 40.0% Moderate | — | — | state-run | Massachusetts Office of Patient Protection (OPP) at Health Policy CommissionNotes~40% of OPP external reviews resolved in patient's favor per OPP 2023 Annual Report referenced by MA HPC. 2024 report not yet located; flag as most-recent-published is 2023. |
| Oregon OR | 2025 | 38.9% Moderate | 278 | 108 | state-run | Oregon Division of Financial Regulation (DFR)NotesOregon DFR IRO Case Detail Report (current through 2025-06-30): 352 cases received, 278 completed full review, 108 overturned or partially overturned (39%), 170 upheld. Excel-format quarterly updates. |
| Washington WA | 2024 | 25.0% Low reversal | — | — | state-run | Washington Office of the Insurance Commissioner (OIC)Notes~25% overturn rate in 2024 per NBC News attribution to WA OIC. 2024 WA OIC Annual Report identified. |
| Arizona AZ | 2014 | 21.0% Low reversal | — | — | state-run | Arizona Department of Insurance and Financial Institutions (DIFI)NotesHistoric KFF-cited figure (21%). DIFI does not publish a current external-review annual report; flagged as stale. |
| West Virginia WV | 2024 | 17.0% Low reversal | — | — | state-run | West Virginia Offices of the Insurance CommissionerNotes~17% overturn rate over the last 5 years (through 2024) per NBC News attribution to WV OIC. Cumulative period rate; not single-year. Significantly below national average. |
| Alabama AL | 2024 | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services)NotesData gap: HHS-administered process; CMS does not publish state-level case totals. Alabama has no state-run external review system. |
| Alaska AK | — | — Data gap | — | — | state-run | Alaska Division of InsuranceNotesData gap: Division publishes annual reports but does not publicly itemize IRO external-review case totals or overturn rates. |
| American Samoa AS | — | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services)NotesU.S. territory using HHS-administered federal process. CMS does not publish jurisdiction-level case totals. |
| Arkansas AR | — | — Data gap | — | — | state-run | Arkansas Insurance DepartmentNotesData gap: Arkansas Insurance Department does not publish a public external-review annual statistics report. |
| Delaware DE | — | — Data gap | — | — | state-run | Delaware Department of InsuranceNotesData gap: Delaware's Independent Health Care Appeals Program (IHCAP) does not publicly post external-review tabular statistics. |
| District of Columbia DC | — | — Data gap | — | — | state-run | DC Department of Insurance Securities and Banking (DISB)NotesData gap: DISB does not publish a dedicated external-review annual statistics document. |
| Florida FL | 2024 | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services)NotesFlorida participates in HHS-administered federal external review (no compliant state-run process for federally regulated plans). FL OIR does not publish corresponding overturn statistics. Data gap on state-level totals. |
| Georgia GA | 2024 | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services)NotesGeorgia uses HHS-administered federal external review process per CMS classification (KFF 2024 listing). OCI took over Patient Rights to Independent Review Act duties from DCH on 2022-07-01 but does not publish overturn statistics. |
| Guam GU | — | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services)NotesU.S. territory using HHS-administered federal process. CMS does not publish jurisdiction-level case totals. |
| Hawaii HI | 2023 | — Data gap | — | — | state-run | Hawaii Insurance Division (DCCA)NotesData gap on count fields: Hawaii does publish an Annual External Review Report (2023 most recent located). Underlying PDF binary not parseable in our pipeline; cite the report URL directly. |
| Idaho ID | — | — Data gap | — | — | state-run | Idaho Department of InsuranceNotesData gap: Idaho DOI does not publish public external-review statistics. |
| Illinois IL | 2024 | — Data gap | — | — | state-run | Illinois Department of Insurance (IDOI)NotesData gap on count fields: IDOI Annual Report to the Governor 2024 references external-review program but tabular case counts not extracted from binary PDF in our pipeline. Hotline: 877-850-4740. |
| Indiana IN | — | — Data gap | — | — | state-run | Indiana Department of InsuranceNotesData gap: IROs must file annual reports with IDOI but the Department does not publish a consolidated public external-review statistics document. |
| Iowa IA | — | — Data gap | — | — | state-run | Iowa Insurance DivisionNotesData gap: Iowa Insurance Division publishes annual reports but does not specifically itemize external-review overturn statistics in a discoverable form. |
| Kentucky KY | — | — Data gap | — | — | state-run | Kentucky Department of InsuranceNotesData gap: Kentucky DOI does not publish public external-review statistics. |
| Louisiana LA | — | — Data gap | — | — | state-run | Louisiana Department of InsuranceNotesData gap: LDOI does not publish public external-review overturn statistics. |
| Maine ME | 2023 | — Data gap | — | — | state-run | Maine Bureau of Insurance (Consumer Health Care Division)NotesMaine's Consumer Health Care Division publishes annual external review report incorporated into Superintendent's 2023 Annual Report. Specific case counts not extracted from binary PDF in our pipeline; cite source URL directly. |
| Michigan MI | 2024 | — Data gap | — | — | state-run | Michigan Department of Insurance and Financial Services (DIFS)NotesData gap on count fields: DIFS publishes PRIRA (Patient's Right to Independent Review Act) decisions individually on its site but does not publish consolidated overturn statistics in a discoverable form. 2024 DIFS Annual Report identified. |
| Mississippi MS | 2024 | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services)NotesMississippi historically classified as relying on HHS-administered federal process. Note KFF 2024 state list only flags 5 states (AL/FL/GA/TX/WI); MS may have shifted classification. Flag for re-verification. |
| Missouri MO | — | — Data gap | — | — | state-run | Missouri Department of Commerce and InsuranceNotesData gap: Missouri DCI does not publish public external-review overturn statistics. |
| Montana MT | — | — Data gap | — | — | state-run | Montana Commissioner of Securities and InsuranceNotesData gap: CSI Montana does not publish public external-review statistics. |
| Nebraska NE | — | — Data gap | — | — | state-run | Nebraska Department of InsuranceNotesData gap: Nebraska DOI does not publish public external-review statistics. Note: NE was previously HHS-administered; KFF 2024 list shows state-run, flag for verification. |
| Nevada NV | — | — Data gap | — | — | state-run | Nevada Division of InsuranceNotesData gap: Nevada Division of Insurance does not publish a discoverable external-review statistics report. |
| New Hampshire NH | — | — Data gap | — | — | state-run | New Hampshire Insurance DepartmentNotesData gap: NHID 2025 Annual Report identified but specific external-review counts not extracted. |
| New Jersey NJ | — | — Data gap | — | — | state-run | New Jersey Department of Banking and Insurance (DOBI) IHCAPNotesData gap on count fields: DOBI's Independent Health Care Appeals Program (IHCAP) publishes periodic reports (48th IHCAP report identified) but case-level statistics not extracted from binary PDF in our pipeline. KFF 1998-era data cited Connecticut + NJ in 50-72% historic range. |
| New Mexico NM | — | — Data gap | — | — | state-run | New Mexico Office of Superintendent of Insurance (OSI)NotesData gap: NM OSI does not publish public external-review overturn statistics. |
| New York NY | 2024 | — Data gap | — | — | state-run | New York Department of Financial Services (DFS)NotesNY DFS publishes the most extensive external-appeal database in the US (searchable: https://www.dfs.ny.gov/public-appeal/search). Aggregate 2024 counts referenced in DFS 2024 Annual Report; specific tables not extracted from binary PDF in our pipeline. Independent dashboard at https://appeal-explorer.persius.org |
| North Dakota ND | — | — Data gap | — | — | state-run | North Dakota Insurance DepartmentNotesData gap: ND Insurance Department does not publish public external-review statistics. |
| Northern Mariana Islands MP | — | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services)NotesU.S. territory using HHS-administered federal process. CMS does not publish jurisdiction-level case totals. |
| Ohio OH | 2019 | — Data gap | — | — | state-run | Ohio Department of InsuranceNotesData gap on count fields: Most recent publicly posted Annual Health Claims External Review Report is 2019. Ohio law requires annual publication but current-year reports not published online; flag as significant transparency gap. |
| Oklahoma OK | — | — Data gap | — | — | state-run | Oklahoma Insurance DepartmentNotesData gap: OID does not publish public external-review statistics. |
| Puerto Rico PR | — | — Data gap | — | — | state-run | Puerto Rico Office of the Insurance CommissionerNotesKFF 2024 classifies Puerto Rico as operating an NAIC-parallel state-run external-review process; OCS does not publish public overturn statistics. |
| Rhode Island RI | — | — Data gap | — | — | state-run | Rhode Island Office of the Health Insurance Commissioner (OHIC)NotesData gap: OHIC does not publish a discoverable external-review statistics document. |
| South Dakota SD | — | — Data gap | — | — | state-run | South Dakota Division of InsuranceNotesData gap: SD Division of Insurance publishes IRO process documentation but no overturn statistics. |
| Tennessee TN | — | — Data gap | — | — | state-run | Tennessee Department of Commerce and Insurance (TDCI)NotesData gap: TDCI returned $17.54M to consumers via mediation in 2024 but does not break out external-review overturn statistics. |
| Texas TX | — | — Data gap | — | — | state-run | Texas Department of Insurance (TDI)NotesData gap on count fields: TDI publishes IRO decisions individually but does not publish consolidated overturn statistics. Note: KFF 2024 lists TX as HHS-administered; TDI operates state-level IRO process for workers' compensation and certifies IROs. Methodology divergence: TX IRO data structure differs materially from CA DMHC IMR; not directly comparable. |
| U.S. Virgin Islands VI | — | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services)NotesU.S. territory using HHS-administered federal process. CMS does not publish jurisdiction-level case totals. |
| Utah UT | — | — Data gap | — | — | state-run | Utah Insurance DepartmentNotesData gap: Utah Insurance Department does not publish public external-review statistics. |
| Vermont VT | — | — Data gap | — | — | state-run | Vermont Department of Financial Regulation (DFR)NotesData gap: Vermont DFR publishes Health Insurers Annual Reports with claims/appeals data but does not specifically itemize external-review overturn rates in a public summary. |
| Virginia VA | — | — Data gap | — | — | state-run | Virginia Bureau of Insurance (State Corporation Commission)NotesData gap: VA Bureau of Insurance does not publish a discoverable external-review statistics report. |
| Wisconsin WI | 2024 | — HHS-administered | — | — | HHS-administered | HHS-Administered Federal External Review (MAXIMUS Federal Services) / Wisconsin OCINotesWisconsin operates partial state external-review framework but classified by KFF (2024) as relying on HHS-administered process for the full external-review pathway. WI OCI 2024 Wisconsin Insurance Report identified at https://oci.wi.gov/Documents/AboutOCI/2024_WIR.pdf |
| Wyoming WY | — | — Data gap | — | — | state-run | Wyoming Department of InsuranceNotesData gap: WY DOI does not publish public external-review statistics. |
Reading note. Denominators are not comparable across jurisdictions. Some states count cases received; some count cases completed; some count completed-and-eligible. California and Maryland publish a complaint-process reversal rate that is broader than the strict IRO-only overturn. See the methodology document for the per-row caveats.
How we built it. What we did not do.
What we did
- Surveyed all 50 state Departments of Insurance plus DC and the 5 U.S. territories.
- Cross-checked KFF's 2024 ACA marketplace data, CMS external-appeals factsheet, and NBC News' 2025 multi-state reporting.
- Anchored every numeric cell to a single primary source URL.
- Flagged five categories of caveat: HHS-administered, cumulative-period, broader-than-IRO, methodology divergence, and data gap.
What we did not do
- Invent numbers for states that do not publish them.
- Roll up a single national average. Denominators are not comparable.
- Split out cancer / oncology subsets. This is the general external-review universe.
- Include Medicare Advantage IRE data — that is a separate federal regime with materially different overturn dynamics.
- Include workers' compensation IMR data.
Apellica (2026). The Apellica External Review Index: U.S. State External-Review Reversal Rates 2026. v1.0. Released 2026-05-19. CC-BY-4.0. https://apellica.com/external-review-index
Press contact: press@apellica.com. Editorial corrections: editorial@apellica.com.
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