Insurance Denial Statistics: The Numbers You Need to Know

Updated February 2026 • 5 min read

Insurance claim denials affect millions of Americans every year. Understanding the scale of the problem — and how often appeals succeed — can help you decide whether to fight your denial.

Key Statistics at a Glance

Note on scope: Many widely cited denial and appeal figures come from ACA Marketplace reporting (HealthCare.gov) and may not reflect employer-sponsored, Medicare, Medicaid, or other plan types. Use these numbers as directional context, not guarantees.

~19%
Of in-network claims denied by ACA marketplace insurers in 2023
Source: KFF analysis of CMS data, 2025
72 hrs
Common expedited appeal decision timeframe for urgent care (many plans)
Note: Exact rules vary by plan type
<1%
Of denied claims are appealed (reported Marketplace data)
Source: KFF analysis of HealthCare.gov data
44%
Internal appeals that overturn the denial (reported Marketplace data)
Source: KFF analysis of HealthCare.gov/CMS Marketplace reporting

Why Don't More People Appeal?

Despite potentially meaningful success rates in some datasets, very few denied claims are appealed. The most common reasons:

  • People don't know they can — Many patients assume a denial is final
  • The process is confusing — Appeal procedures vary by insurer and state
  • Writing an appeal letter is hard — Most people don't know what to say or cite
  • Time pressure — People dealing with health issues have limited energy for paperwork
  • Small claim amounts — Some denials seem "not worth the effort" (though they add up)

Most Commonly Denied Procedures

While denial rates vary by insurer and plan, certain categories face higher denial rates:

  • Mental health and substance abuse treatment — Often denied as "not medically necessary"
  • Physical therapy and rehabilitation — Frequently denied after a set number of sessions
  • Advanced imaging (MRI, CT scans) — Often requires prior authorization
  • Specialty medications — Especially biologics and brand-name drugs
  • Surgical procedures — Particularly elective or reconstructive surgery
  • Emergency room visits — Retroactively denied as "not a true emergency"

The Cost of Not Appealing

When patients don't appeal, they either:

  • Pay out of pocket for treatment they should have been covered for
  • Skip necessary medical care entirely
  • Accumulate medical debt

Appeal success rates can be meaningful, but they vary a lot by plan type and denial category. If you don't appeal, you may be leaving money — and potentially your health — on the table.

Make Your Appeal Count

The biggest barrier to appealing is the difficulty of writing a strong appeal letter. MedAppeals removes that barrier by using AI to draft professional appeal letters in seconds.

Appealing Is Often Worth It

Join the patients who fought back — and won.

Start Your Free Appeal