How Often Do Insurance Appeals Succeed? The Data

Health insurance appeal success rates are far higher than most patients expect — yet fewer than 1 in 1,000 denied claims result in a formal appeal. The data shows that 40–60% of appeals succeed when properly filed. Here is what the research actually says.

Most People Never Appeal — and That Is Exactly WhatInsurers Count On

A 2023 Kaiser Family Foundation study found that insurers denied approximately 17% of in-network claims submitted by ACA marketplace enrollees. Of those denied claims, fewer than 1 in 1,000 enrollees filed an internal appeal. Yet among those who did appeal, approximately 40–60% of internal appeals were decided in the consumer's favor.

The math is stark: the majority of people who have a validbasis to appeal simply do not. The system is designed around that assumption.

Internal Appeal Success Rates by Category

Medical necessity denials (CO-50 and similar)

Internal appeal success rates for medical necessity denials range from 40–60% when properly documented. Cases where the insurer's stated reason is directly contradicted by clinical records have significantly higher success rates — ClaimCompass identifies these as factual contradictions and they are among the strongest appeal categories.

Prior authorization denials

Success rates for prior authorization appeals are similar to medical necessity — approximately 40–55% overall. Cases involving step therapy exceptions and emergency situations have higher success rates.

Mental health and behavioral health

Mental health appeal success rates have improved since enforcement of the Mental Health Parity Act intensified. Parity-based appeals have seen success rates as high as 60–70% in states with active enforcement.

External independent review

External review is the most powerful tool available. Approximately 40–45% of external reviews result in the insurer's decision being overturned. For urgent care and concurrent care reviews, overturn rates are higher.

Medicare Appeal Success Rates

Medicare appeal success rates increase dramatically athigher levels:

• Redetermination (Level 1): approximately 10–20% overturnrate

• QIC Reconsideration (Level 2): approximately 15–25%overturn rate

• ALJ Hearing (Level 3): approximately 40–55% overturn rate

• Medicare Appeals Council (Level 4): variable

The data shows that persistence pays. Most Medicare beneficiaries who eventually win their appeals do so at Level 3 — the hearing level.

VA Benefits Appeal Success Rates

VA benefits appeals data shows:

• Supplemental Claims with new and relevant evidence: higherapproval rates than original claims

• Board of Veterans' Appeals — Direct Review: approximately30–35% grant rate

• Board of Veterans' Appeals — Hearing: approximately 35–45%grant rate

• Representation matters: claimants represented by accredited attorneys or VSOs have consistently higher approval rates

Social Security Disability Appeal Success Rates

• Initial applications: approximately 35% approval rate

• Reconsideration: approximately 10–15% approval rate

• ALJ Hearing: approximately 45–55% approval rate

• With attorney or advocate representation at hearing: approximately 55–65% approval rate

The data for Social Security is the clearest: most people who ultimately win their disability claims win at the hearing level, not at reconsideration.

What the Data Tells Us

Three patterns emerge consistently across every benefits category:

Most valid appeals are never filed

The gap between the percentage of claims denied and the percentage of appeals filed is enormous. Tens of millions of dollars in legitimate benefits go uncollected every year because people give up.

Persistence dramatically improves outcomes

Success rates increase at higher appeal levels across virtually every category. The people who win are often the people who kept going.

Documentation is the single biggest predictor of success

The most common reason appeals fail is insufficient documentation — not insufficient merit. A well-documented appeal of a marginal case often succeeds. A poorly documented appeal of a strong case often fails.

Frequently Asked Questions

How often do insurance appeals succeed?

Data shows internal appeals succeed 40–60% of the time depending on denial type, with external reviews succeeding about 40% of the time overall. Medical necessity and prior authorization denials have some of the highest overturn rates.

Is it worth appealing a health insurance denial?

Yes — most people who file appeals win at least partial relief. The challenge is that fewer than 1 in 10 people who receive a denial actually file an appeal, so the population of appealed cases skews toward stronger cases, but the underlying success rate is genuinely high.

Do insurance companies have to tell you why a claim was denied?

Yes. Under ACA rules and most state laws, insurers must provide a written denial notice with the specific reason for denial, the clinical criteria used, and instructions for how to appeal.

How ClaimCompass Helps

ClaimCompass generates formally documented appeal lettersthat include the clinical citations, policy references, and specific argumentsthat drive appeal success rates.

Upload your denial at myclaimcompass.ai for a free analysis.