Dataset · v1.0 · Released 2026-05-19

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.

Download full CSV Methodology (PDF)Skip to the table ↓

Jurisdictions covered

With measured rate

State-run programs

HHS-administered

Released by Apellica under CC-BY-4.0. Reuse it. Cite it. Improve it. Open an issue or send corrections to editorial@apellica.com.

What this dataset is

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The single largest finding of the exercise is that transparency itself is the lottery. 42 of 56 jurisdictions do not publish discoverable current external-review statistics.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.

The dataset

External-review reversal rate by jurisdiction.

Sorted by reversal rate (highest first). Click any row to open the source.

Jurisdiction	Year	Reversal rate	Cases	Overturned	System	Regulator
Connecticut CT	2024	80.0% High reversal	n/a	n/a	state-run	Connecticut Insurance Department / Office of the Healthcare Advocate Notes Healthcare 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	n/a	n/a	state-run	California Department of Managed Health Care (DMHC) Notes Headline: ~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	n/a	n/a	state-run	Maryland Insurance Administration (MIA) Notes MIA 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) Notes Smart 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	n/a	n/a	state-run	Kansas Insurance Department Notes ~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) Notes PA 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	n/a	n/a	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	n/a	n/a	state-run	Minnesota Department of Commerce Notes 43% 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	n/a	n/a	state-run	South Carolina Department of Insurance Notes ~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	n/a	n/a	state-run	Massachusetts Office of Patient Protection (OPP) at Health Policy Commission Notes ~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) Notes Oregon 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	n/a	n/a	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	n/a	n/a	state-run	Arizona Department of Insurance and Financial Institutions (DIFI) Notes Historic 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	n/a	n/a	state-run	West Virginia Offices of the Insurance Commissioner Notes ~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	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) Notes Data gap: HHS-administered process; CMS does not publish state-level case totals. Alabama has no state-run external review system.
Alaska AK	n/a	n/a No published rate found	n/a	n/a	state-run	Alaska Division of Insurance Notes Data gap: Division publishes annual reports but does not publicly itemize IRO external-review case totals or overturn rates.
American Samoa AS	n/a	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) Notes U.S. territory using HHS-administered federal process. CMS does not publish jurisdiction-level case totals.
Arkansas AR	n/a	n/a No published rate found	n/a	n/a	state-run	Arkansas Insurance Department Notes Data gap: Arkansas Insurance Department does not publish a public external-review annual statistics report.
Delaware DE	n/a	n/a No published rate found	n/a	n/a	state-run	Delaware Department of Insurance Notes Data gap: Delaware's Independent Health Care Appeals Program (IHCAP) does not publicly post external-review tabular statistics.
District of Columbia DC	n/a	n/a No published rate found	n/a	n/a	state-run	DC Department of Insurance Securities and Banking (DISB) Notes Data gap: DISB does not publish a dedicated external-review annual statistics document.
Florida FL	2024	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) Notes Florida 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	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) Notes Georgia 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	n/a	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) Notes U.S. territory using HHS-administered federal process. CMS does not publish jurisdiction-level case totals.
Hawaii HI	2023	n/a No published rate found	n/a	n/a	state-run	Hawaii Insurance Division (DCCA) Notes Data 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	n/a	n/a No published rate found	n/a	n/a	state-run	Idaho Department of Insurance Notes Data gap: Idaho DOI does not publish public external-review statistics.
Illinois IL	2024	n/a No published rate found	n/a	n/a	state-run	Illinois Department of Insurance (IDOI) Notes Data 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	n/a	n/a No published rate found	n/a	n/a	state-run	Indiana Department of Insurance Notes Data gap: IROs must file annual reports with IDOI but the Department does not publish a consolidated public external-review statistics document.
Iowa IA	n/a	n/a No published rate found	n/a	n/a	state-run	Iowa Insurance Division Notes Data gap: Iowa Insurance Division publishes annual reports but does not specifically itemize external-review overturn statistics in a discoverable form.
Kentucky KY	n/a	n/a No published rate found	n/a	n/a	state-run	Kentucky Department of Insurance Notes Data gap: Kentucky DOI does not publish public external-review statistics.
Louisiana LA	n/a	n/a No published rate found	n/a	n/a	state-run	Louisiana Department of Insurance Notes Data gap: LDOI does not publish public external-review overturn statistics.
Maine ME	2023	n/a No published rate found	n/a	n/a	state-run	Maine Bureau of Insurance (Consumer Health Care Division) Notes Maine'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	n/a No published rate found	n/a	n/a	state-run	Michigan Department of Insurance and Financial Services (DIFS) Notes Data 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	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) Notes Mississippi 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	n/a	n/a No published rate found	n/a	n/a	state-run	Missouri Department of Commerce and Insurance Notes Data gap: Missouri DCI does not publish public external-review overturn statistics.
Montana MT	n/a	n/a No published rate found	n/a	n/a	state-run	Montana Commissioner of Securities and Insurance Notes Data gap: CSI Montana does not publish public external-review statistics.
Nebraska NE	n/a	n/a No published rate found	n/a	n/a	state-run	Nebraska Department of Insurance Notes Data 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	n/a	n/a No published rate found	n/a	n/a	state-run	Nevada Division of Insurance Notes Data gap: Nevada Division of Insurance does not publish a discoverable external-review statistics report.
New Hampshire NH	n/a	n/a No published rate found	n/a	n/a	state-run	New Hampshire Insurance Department Notes Data gap: NHID 2025 Annual Report identified but specific external-review counts not extracted.
New Jersey NJ	n/a	n/a No published rate found	n/a	n/a	state-run	New Jersey Department of Banking and Insurance (DOBI) IHCAP Notes Data 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	n/a	n/a No published rate found	n/a	n/a	state-run	New Mexico Office of Superintendent of Insurance (OSI) Notes Data gap: NM OSI does not publish public external-review overturn statistics.
New York NY	2024	n/a No published rate found	n/a	n/a	state-run	New York Department of Financial Services (DFS) Notes NY 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	n/a	n/a No published rate found	n/a	n/a	state-run	North Dakota Insurance Department Notes Data gap: ND Insurance Department does not publish public external-review statistics.
Northern Mariana Islands MP	n/a	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) Notes U.S. territory using HHS-administered federal process. CMS does not publish jurisdiction-level case totals.
Ohio OH	2019	n/a No published rate found	n/a	n/a	state-run	Ohio Department of Insurance Notes Data 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	n/a	n/a No published rate found	n/a	n/a	state-run	Oklahoma Insurance Department Notes Data gap: OID does not publish public external-review statistics.
Puerto Rico PR	n/a	n/a No published rate found	n/a	n/a	state-run	Puerto Rico Office of the Insurance Commissioner Notes KFF 2024 classifies Puerto Rico as operating an NAIC-parallel state-run external-review process; OCS does not publish public overturn statistics.
Rhode Island RI	n/a	n/a No published rate found	n/a	n/a	state-run	Rhode Island Office of the Health Insurance Commissioner (OHIC) Notes Data gap: OHIC does not publish a discoverable external-review statistics document.
South Dakota SD	n/a	n/a No published rate found	n/a	n/a	state-run	South Dakota Division of Insurance Notes Data gap: SD Division of Insurance publishes IRO process documentation but no overturn statistics.
Tennessee TN	n/a	n/a No published rate found	n/a	n/a	state-run	Tennessee Department of Commerce and Insurance (TDCI) Notes Data gap: TDCI returned $17.54M to consumers via mediation in 2024 but does not break out external-review overturn statistics.
Texas TX	n/a	n/a No published rate found	n/a	n/a	state-run	Texas Department of Insurance (TDI) Notes Data 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	n/a	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) Notes U.S. territory using HHS-administered federal process. CMS does not publish jurisdiction-level case totals.
Utah UT	n/a	n/a No published rate found	n/a	n/a	state-run	Utah Insurance Department Notes Data gap: Utah Insurance Department does not publish public external-review statistics.
Vermont VT	n/a	n/a No published rate found	n/a	n/a	state-run	Vermont Department of Financial Regulation (DFR) Notes Data 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	n/a	n/a No published rate found	n/a	n/a	state-run	Virginia Bureau of Insurance (State Corporation Commission) Notes Data gap: VA Bureau of Insurance does not publish a discoverable external-review statistics report.
Wisconsin WI	2024	n/a HHS-administered	n/a	n/a	HHS-administered	HHS-Administered Federal External Review (MAXIMUS Federal Services) / Wisconsin OCI Notes Wisconsin 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	n/a	n/a No published rate found	n/a	n/a	state-run	Wyoming Department of Insurance Notes Data 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.

Explore the data

Sort it, filter it, see the spread.

The chart plots only the jurisdictions that publish a figure. The table below is every jurisdiction we surveyed. Both are the exact numbers each authority reported, with the “what this is / is not” caveats attached.

Measured reversal rate by jurisdiction (14 of 56 publish one)

What this is: the share of external-review cases a jurisdiction reports as overturned in full or part, exactly as the jurisdiction published it. What it is not: a like-for-like ranking. Denominators differ (cases received vs. completed vs. eligible), some figures are cumulative multi-year, and a few are complaint-process rates broader than IRO-only review. Empty jurisdictions publish no figure at all.

Sortable, filterable table of external-review reversal rates by U.S. jurisdiction.
				Overturned	System
ConnecticutCT	2024	80.0%	n/a	n/a	state-run
CaliforniaCA	2024	72.7%	n/a	n/a	state-run
MarylandMD	2024	66.8%	n/a	n/a	state-run
North CarolinaNC	2024	54.3%	282	153	state-run
KansasKS	2024	54.0%	n/a	n/a	state-run
PennsylvaniaPA	2025	48.4%	1,353	655	state-run
ColoradoCO	2024	44.0%	n/a	n/a	state-run
MinnesotaMN	2024	43.0%	n/a	n/a	state-run
South CarolinaSC	2024	43.0%	n/a	n/a	state-run
MassachusettsMA	2023	40.0%	n/a	n/a	state-run
OregonOR	2025	38.9%	278	108	state-run
WashingtonWA	2024	25.0%	n/a	n/a	state-run
ArizonaAZ	2014	21.0%	n/a	n/a	state-run
West VirginiaWV	2024	17.0%	n/a	n/a	state-run
AlabamaAL	2024	n/a	n/a	n/a	HHS-administered
AlaskaAK	n/a	n/a	n/a	n/a	state-run
American SamoaAS	n/a	n/a	n/a	n/a	HHS-administered
ArkansasAR	n/a	n/a	n/a	n/a	state-run
DelawareDE	n/a	n/a	n/a	n/a	state-run
District of ColumbiaDC	n/a	n/a	n/a	n/a	state-run
FloridaFL	2024	n/a	n/a	n/a	HHS-administered
GeorgiaGA	2024	n/a	n/a	n/a	HHS-administered
GuamGU	n/a	n/a	n/a	n/a	HHS-administered
HawaiiHI	2023	n/a	n/a	n/a	state-run
IdahoID	n/a	n/a	n/a	n/a	state-run
IllinoisIL	2024	n/a	n/a	n/a	state-run
IndianaIN	n/a	n/a	n/a	n/a	state-run
IowaIA	n/a	n/a	n/a	n/a	state-run
KentuckyKY	n/a	n/a	n/a	n/a	state-run
LouisianaLA	n/a	n/a	n/a	n/a	state-run
MaineME	2023	n/a	n/a	n/a	state-run
MichiganMI	2024	n/a	n/a	n/a	state-run
MississippiMS	2024	n/a	n/a	n/a	HHS-administered
MissouriMO	n/a	n/a	n/a	n/a	state-run
MontanaMT	n/a	n/a	n/a	n/a	state-run
NebraskaNE	n/a	n/a	n/a	n/a	state-run
NevadaNV	n/a	n/a	n/a	n/a	state-run
New HampshireNH	n/a	n/a	n/a	n/a	state-run
New JerseyNJ	n/a	n/a	n/a	n/a	state-run
New MexicoNM	n/a	n/a	n/a	n/a	state-run
New YorkNY	2024	n/a	n/a	n/a	state-run
North DakotaND	n/a	n/a	n/a	n/a	state-run
Northern Mariana IslandsMP	n/a	n/a	n/a	n/a	HHS-administered
OhioOH	2019	n/a	n/a	n/a	state-run
OklahomaOK	n/a	n/a	n/a	n/a	state-run
Puerto RicoPR	n/a	n/a	n/a	n/a	state-run
Rhode IslandRI	n/a	n/a	n/a	n/a	state-run
South DakotaSD	n/a	n/a	n/a	n/a	state-run
TennesseeTN	n/a	n/a	n/a	n/a	state-run
TexasTX	n/a	n/a	n/a	n/a	state-run
U.S. Virgin IslandsVI	n/a	n/a	n/a	n/a	HHS-administered
UtahUT	n/a	n/a	n/a	n/a	state-run
VermontVT	n/a	n/a	n/a	n/a	state-run
VirginiaVA	n/a	n/a	n/a	n/a	state-run
WisconsinWI	2024	n/a	n/a	n/a	HHS-administered
WyomingWY	n/a	n/a	n/a	n/a	state-run

Figures are reproduced exactly as each jurisdiction published them. Read the methodology for per-row caveats, or download the CSV.

Methodology summary

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.

Full methodology (PDF)Markdown source CSV

Reuse this dataset

Built to be cited, embedded, and corrected.

Dataset v1.0 · resource package last updated 2026-09-04. Released under CC-BY-4.0: free to redistribute and adapt with attribution.

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Methodology (markdown) →

Caveats + full per-row source table.

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Fields, license, coverage descriptor.

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<iframe
  src="https://apellica.com/external-review-index/embed"
  title="Apellica External Review Index — state reversal rates"
  width="100%" height="900" loading="lazy"
  style="border:1px solid #e2e2e2;max-width:820px"></iframe>
<p style="font:13px/1.5 system-ui,sans-serif;color:#555;max-width:820px">
  Source: <a href="https://apellica.com/external-review-index">Apellica External
  Review Index</a> (CC-BY-4.0).
</p>

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Source: Apellica External Review Index (CC-BY-4.0). https://apellica.com/external-review-index

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The odds gap →The transparency lottery →Rate by state →

How to cite this dataset

Apellica (2026). The Apellica External Review Index: U.S. State External-Review Reversal Rates 2026. v1.0. Released 2026-05-19; resource package updated 2026-09-04. CC-BY-4.0. https://apellica.com/external-review-index

Researchers and journalists: link a specific figure to its stable per-state URL, e.g. apellica.com/external-review-index/west-virginia. Attribution is required by the license; a link back to apellica.com/external-review-index satisfies it.

Corrections & updates

Found an error, or a newer state report? Email editorial@apellica.com with (1) the jurisdiction, (2) the value or source you believe is correct, and (3) a public-record URL. Verified corrections are folded into the next dated resource update. Press contact: press@apellica.com.

Apellica is an independent appeal-preparation service. It is not a regulator, a law firm, a Medicare entity, or a medical provider. This asset republishes public regulatory data as a free research resource; it contains no patient-identifying information.

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