Highest CMS Claim Denial Rates (185 Issuers)

CMS Transparency in Coverage denial rates across 185 issuers (185 rows). Top 10 by denial rate, compared with the top 10 by denied-claim volume.

Research period:

Compiled by PlainInsurer on 2026-08-19

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 185 individual-market issuers in the CMS Transparency in Coverage data, the highest-rate filing shown here is Moda Health Plan, Inc. in AK at 47.0%. 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 185 insurer-state combinations in CMS Transparency in Coverage data, which filings carry the highest reported in-network claim denial rate, and which filings report the most denied claims on the same 1,000-claim floor?

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.

Highest CMS-reported denial rate

Insurer-state filings with more than 1,000 received claims, not an all-products rate

% denied

What this shows Each bar is one CMS insurer-state filing. A high rate on a small book is not evidence of the most denied claims.

Source CMS Transparency in Coverage Public Use Files As of PY2026

Most CMS-reported denied claims

Same 1,000-claim floor, ordered by denied count rather than rate

denied claims

What this shows Denied-claim count is a volume rank. It is not a restatement of the rate ranking on the left.

Source CMS Transparency in Coverage Public Use Files As of PY2026

Moda Health Plan, Inc. in AK reports the highest in-network denial rate at 47.0% on 204,058 received claims. Blue Cross Blue Shield of Texas in TX reports the most denied claims (11,935,065) at 19.4% - a different rank, not a second reading of the same list.

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 Moda Health Plan, Inc. AK 204,058 95,902 47.0%
2 UnitedHealthcare of Illinois, Inc. IL 579,960 249,677 43.1%
3 Imperial Insurance Companies, Inc. TX 4,307 1,706 39.6%
4 Imperial Insurance Companies, Inc. AZ 3,717 1,396 37.6%
5 CareSource North Carolina Co. NC 207,708 76,854 37.0%
6 Select Health of South Carolina SC 141,484 51,650 36.5%
7 Oscar Buckeye State Insurance Corp. OH 1,910,531 694,493 36.4%
8 Molina Healthcare of Illinois, Inc. IL 101,667 36,626 36.0%
9 UnitedHealthcare Community Plan, Inc. MI 1,110,639 395,425 35.6%
10 UnitedHealthcare Insurance Company LA 1,553,306 549,914 35.4%

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.

Findings

Top entity in the ranking

The top-ranked record in this dataset is Moda Health Plan, Inc., with a denial rate of 47.0%. 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 (47.0%) and the 10th-ranked record (35.4%) 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.

Related data

Sources