Top 10 US Insurers by CMS-Reported Claim Denial Rate
CMS Transparency in Coverage claim-denial rate across 200+ insurer-state combinations, updated automatically as new CMS filings are processed.
Research period:
What this ranks: the CMS-reported in-network claim-denial rate for ACA-marketplace plans only, not financial strength, customer service, or which insurer is right for you. Coverage needs, state availability, and price vary by person, compare quotes and see the full methodology before choosing a plan.
The direct answer
Which health insurer reports the highest claim-denial rate?
Among the 177 individual-market issuers in the CMS Transparency in Coverage data, the highest-rate filing shown here is AmeriHealth Caritas Florida, Inc. in FL at 63.8%. This is an insurer-state filing with more than 1,000 received claims, not an employer-plan or all-products measure. For an insurer-level ranking aggregated across its reporting states, see health insurers by claim-denial rate.
Research question
Among the 200+ insurer-state combinations in CMS Transparency in Coverage data, which insurers carry the highest reported in-network claim denial rate, and what does the appeals-overturn rate look like for the top of the distribution?
Methodology
This ranking reflects the 10 insurers with the highest claim-denial rates, drawn from the Centers for Medicare & Medicaid Services' Transparency in Coverage Public Use Files. Every figure updates automatically as new CMS filings are processed; nothing on this page is hand-entered.
Coverage and exclusions: CMS occasionally suppresses values for confidentiality, small sample size, or quality control, and suppressed rows are excluded from this ranking rather than shown as zero. If CMS later revises a figure, the revised value replaces the old one automatically the next time the portal's data is refreshed.
Data provenance: CMS publishes the Transparency in Coverage files on its own release schedule. We pull each release as it becomes available and normalize it into our database; a later release simply supersedes the one before it, so readers never see a mix of old and new figures on the same page.
Comparability across years: when CMS revises its release schedule, definitions, or coverage, we note the affected years on the methodology page so readers can compare like-with-like rather than across a changed measurement.
Editorial governance: PlainInsurer publishes its editorial policy and corrections process. If an insurer disputes a figure attributed to it, the correction is checked against the official CMS record before any change is made.
Every number on this page can be traced back to its CMS source by following the entity links and the citation below, so independent verification never requires anything beyond the original public source.
See the methodology page for the complete ETL pipeline, source vintage, and column lineage.
Top 10 US Insurers by CMS-Reported Claim Denial Rate
Live data: reflects the current CMS Transparency in Coverage snapshot
The ranked top 10
Every row below reflects the current 10-record dataset. Reload the page after new CMS data is processed to see the latest values.
| # | Insurer | State | Claims received | Claims denied | Denial rate % |
|---|---|---|---|---|---|
| 1 | AmeriHealth Caritas Florida, Inc. | FL | 37,309 | 23,787 | 63.8% |
| 2 | UnitedHealthcare Insurance Company | LA | 286,437 | 151,944 | 53.0% |
| 3 | AmeriHealth Caritas VIP Next, Inc. | DE | 3,688 | 1,910 | 51.8% |
| 4 | UnitedHealthcare Insurance Company | AL | 1,044,392 | 508,004 | 48.6% |
| 5 | CareSource North Carolina Co. | NC | 10,705 | 4,891 | 45.7% |
| 6 | UnitedHealthcare Community Plan, Inc. | MI | 258,752 | 117,736 | 45.5% |
| 7 | Select Health of South Carolina | SC | 75,741 | 34,455 | 45.5% |
| 8 | UnitedHealthcare Insurance Company | KS | 413,551 | 181,789 | 44.0% |
| 9 | UnitedHealthcare of Ohio, Inc. | OH | 448,360 | 194,892 | 43.5% |
| 10 | UnitedHealthcare of Illinois, Inc. | IL | 579,960 | 249,677 | 43.1% |
Source: Centers for Medicare & Medicaid Services, CMS Transparency in Coverage Public Use Files. Values reflect the current dataset, refreshed as new CMS filings are processed. Centers for Medicare & Medicaid Services, CMS Transparency in Coverage Public Use Files. Values reflect the current dataset, refreshed as new CMS filings are processed.
Findings
Top entity in the ranking
The top-ranked record in this dataset is AmeriHealth Caritas Florida, Inc., with a denial rate of 63.8%. The full top-10 set is rendered in the table above. When the source agency publishes a revision, the ranking and the prose around it update automatically.
Distribution shape
The gap between the top-ranked record (63.8%) and the 10th-ranked record (43.1%) characterizes how concentrated the top of the distribution is. Where the top value is many multiples of the median value of the visible set, the population is highly concentrated, a small number of entities accumulate the bulk of the measured quantity. Where the top and bottom of the visible set are close together, the distribution is relatively flat across the top end. The full distribution beyond this top-10 cut is summarized in the aggregate context section below and explored in the linked entity profiles.
Aggregate context
The figures below situate the top-10 ranking against the full population: how many insurer-state combinations exist in total, and what the average denial rate looks like across all of them.
Source provenance
The records in this ranking originate from Centers for Medicare & Medicaid Services, specifically the CMS Transparency in Coverage Public Use Files. Plaininsurer ingests the source vintage published by the agency and keeps this page current, there is no static export carrying stale numbers, and a newly published dataset is reflected here within hours. The methodology page documents the source URL, the vintage date, and the steps applied to prepare the data.
Why this ranking matters
Rankings like this one let a reader scan a population quickly and identify outliers, concentrations, and patterns that warrant deeper investigation. The detail pages linked from each entity in the table above give the full per-entity context: time-series history where available, related metrics from adjacent tables, and links onward to the underlying source records. The methodology page explains how an entity earns inclusion in the dataset and how the ranking column is computed at the source.
What this analysis cannot tell us
CMS Transparency in Coverage data covers ACA-marketplace (qualified health plans) and reflects in-network claim activity for the displayed plan year. Out-of-network denials, commercial group plans, Medicare Advantage, Medicaid managed care, and self-insured ERISA plans report under separate regimes not captured by this dataset. Denial rate is calculated as denied claims divided by received claims and reflects insurer claim-adjudication outcomes; a high denial rate may reflect documentation issues, plan-design exclusions, network-access factors, or clinical-necessity determinations. Appeals overturn rate reflects the share of formal appeals that resulted in the insurer reversing the denial. Filter applied to base table: rows with at least 1,000 claims received in the displayed period to surface insurers with meaningful sample sizes. This page reports figures as recorded in CMS filings; it is not advice about coverage purchase, claim disputes, or appeals strategy.
Secondary cut from the same source
Top 10 insurers by CMS-reported appeals overturn rate (denials reversed on appeal)
Sources
- CMS, Transparency in Coverage Public Use Files - https://www.cms.gov/marketplace/resources/data
- CMS, Qualified Health Plan Issuer Public Use Files - https://www.cms.gov/marketplace/resources/data
- Healthcare.gov, Plan Year Data - https://www.healthcare.gov/