Insurance9 min read
How to fight an insurance claim denial (and win)
The short answer
A large share of denied claims are overturned on appeal — insurers count on you accepting the first no. Get the denial reason in writing, match it against your policy language and the claim codes, fix the specific deficiency (coding error, missing documentation, wrong classification), and escalate: internal appeal, then your state's external review or insurance department. Most winnable denials die at the first two steps.
Step 1: Decode the actual reason
Denials sound final and mean specific things. "Not medically necessary" = a clinical judgment you can challenge with your doctor's evidence. "Out of network" = check whether the No Surprises Act or network-adequacy rules apply. "Not a covered service" = a policy-language fight, and policy language is negotiable terrain. "Timely filing" = check whose fault the delay was — provider filing errors are not yours. Get the EOB or denial letter, the exact code, and the policy section they cite. Every appeal is built on those three documents.
Step 2: Fix the cheap errors first
A large slice of denials are paperwork: wrong CPT or diagnosis code, a transposed digit in the policy number, a referral that was obtained but never attached, a claim filed to the wrong address. These die with a corrected resubmission, not an appeal. Call the provider's billing office — they resubmit corrected claims daily and it costs them nothing. For medical-necessity denials, the fix is a letter from your treating physician citing the clinical evidence and guidelines; insurers reverse for a good doctor letter at a remarkable rate.
Step 3: The formal internal appeal
File the written appeal within the deadline (usually 180 days for health claims) and make it boring: the claim, the denial reason, the policy language that covers you, the evidence, and the specific correction demanded. Attach everything — the corrected codes, the doctor's letter, the relevant policy page with the covering paragraph highlighted. Reference their deadlines too: insurers must respond within set windows (30 days pre-service, 60 post-service for health), and a missed deadline can mean an automatic win or an immediate external-review ticket.
Step 4: External review — the closer
If the internal appeal fails, health claims go to independent external review — a physician reviewer with no stake in your insurer, whose decision binds them. External review overturns a significant share of medical-necessity denials. For property and auto, the equivalents are your state insurance department complaint (insurers hate regulator files) and the policy's appraisal clause (each side picks an appraiser, an umpire decides — heavily used on roofing and storm claims). Both are free or nearly free, and both move insurers who ignored you for months.
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Start freeQuestions people actually ask
- How long do I have to appeal a denial?
- Health insurance: typically 180 days for the internal appeal, 4 months for external review after the final denial. Property and auto policies vary — some as short as 60 days for supplemental documentation. The deadline is in the denial letter; calendar it the day the letter arrives, because a missed deadline usually ends the matter regardless of merit.
- Does appealing cost anything?
- Internal appeals and external health reviews are free. State insurance department complaints are free. The property appraisal clause costs your appraiser's fee (a few hundred dollars, often recoverable). Public adjusters and claim attorneys take 10–33% of the recovery — worth it on five-figure property claims, overkill on a denied MRI.
- The insurer says the treatment is "experimental" — is that final?
- No — "experimental/investigational" is a policy-language fight, and insurers apply it too broadly. Counter with the clinical literature, the relevant medical society guidelines, and whether the same service is covered for other diagnoses. External reviewers see through overbroad experimental labels regularly, especially when the doctor's letter cites accepted standards of care.
- Should I get a lawyer for a denied claim?
- For health claims under a few thousand dollars, no — the appeal machinery works and is free. For large property claims, bad-faith patterns (lowballing documented losses, endless document loops), or disability/long-term-care denials, a policyholder attorney often pays for itself several times over — most work on contingency. Start with the free steps; lawyer up when the money or the pattern justifies it.