If your health insurance claim was denied, you are far from alone. In 2024, insurers on HealthCare.gov denied 19% of in-network claims, about 85 million in total. The good news is that many denials come down to fixable problems. Here are the most common reasons, and what you can do about each one.
How often claims are denied
Denial rates vary widely between insurers. According to a KFF analysis of 2024 data, rates ranged from 3% at some insurers to 36% at others. That gap is one reason to look at more than the premium when you pick a plan.
Despite how common denials are, fewer than 1% of denied claims are ever appealed. Many people assume the first answer is final. It often is not.
The most common reasons for a denial
1. Paperwork and billing errors
Administrative problems were behind about a quarter of denial reasons in 2024. That includes missing information, a wrong code, a typo in your member ID, or a claim filed after the deadline.
How to fix it: Call your doctor's billing office and ask them to check the claim and resubmit it with the correct details. This is often the fastest fix of all.
2. The service isn't covered by your plan
About 13% of denial reasons were for excluded services, meaning care your plan does not cover at all. Common examples include some cosmetic procedures, certain weight-loss treatments, and some alternative therapies.
How to fix it: Check your plan's Summary of Benefits and Coverage. If your doctor believes the treatment is medically necessary for your condition, an appeal with supporting evidence may still succeed.
3. No prior authorization or referral
Some plans require approval before certain tests, procedures or specialist visits. Missing that step accounted for about 9% of denial reasons.
How to fix it: Ask your doctor's office to request authorization after the fact and to explain why the care was needed. For future care, confirm approval in writing before your appointment.
4. "Not medically necessary"
About 5% of denial reasons were that the insurer judged the care was not medically necessary.
How to fix it: Ask your doctor for a letter of medical necessity explaining why this treatment was right for you, citing your history and any treatments you have already tried.
5. Out-of-network care
Seeing a doctor or using a facility outside your plan's network can lead to a denial or a much higher bill, especially with HMO and EPO plans.
How to fix it: If it was an emergency, or if you had no choice of provider, federal surprise-billing protections may apply. Ask your insurer to reprocess the claim at in-network rates.
What to do next
- Read your denial letter or Explanation of Benefits. It must state the reason for the denial.
- Call your insurer and ask exactly what is needed to fix the claim. Write down the date, the representative's name and a reference number.
- Talk to your doctor's billing office. Many denials are solved by a corrected claim.
- File an appeal if needed. You generally have 180 days from the denial notice to file an internal appeal.
The bottom line
A denied claim is common, but it is not always the end of the road. Find out the reason, fix what can be fixed, and appeal when you have the evidence. A short phone call or a doctor's letter can be the difference between a large bill and full coverage.
This article is for general information only and is not legal, medical or insurance advice. Coverage rules vary by plan and state.