How do you appeal a denied insurance claim?

Start by obtaining the specific reason in writing, which insurers are required to provide, along with the plan language they relied on. Denials fall into recognizable categories: administrative errors such as an incorrect billing code or missing prior authorization, medical necessity determinations, out-of-network issues, and exclusions. The first category is the most common and the easiest to reverse, frequently with a phone call to the provider's billing office asking them to resubmit with corrected coding, so establishing which category applies determines whether you need an appeal at all.

For health insurance, federal law gives you a two-stage process. The internal appeal goes to the insurer, generally within 180 days of the denial, and requires them to conduct a full and fair review. If that fails, you have the right to an external review by an independent organization not affiliated with the insurer, and that decision is binding on the plan. Deadlines are strict and expedited timelines exist for urgent situations where waiting would jeopardize your health. Strengthen the appeal with a letter of medical necessity from your treating physician addressing the specific reason cited, supporting clinical literature where relevant, and a clear statement of what plan provision you believe entitles you to coverage.

Two practical points. Documentation discipline matters: keep a log of every call with date, time, representative name, and reference number, and follow verbal conversations with written confirmation, because appeals often turn on a record of what was said. And escalation channels outside the process exist and work, including your state insurance commissioner, who accepts complaints and has authority insurers respond to, and for employer-sponsored plans, your HR benefits team, who have leverage with the carrier that an individual does not. For property and auto claims, the analogous steps are requesting the adjuster's report, obtaining independent estimates, invoking the appraisal clause that most policies contain for disputes over amount, and filing with the state regulator.