How to appeal a health insurance claim denial

A denial letter reads like a verdict, but in most cases it is the first step in a process with defined rights. The plan must tell you why it denied the claim. It must give you a way to appeal to someone who was not involved in the first decision. If it still says no, many denials can go to an independent reviewer whose decision binds the plan. The weak point is time: the deadlines are real, they start when you receive the notice, and most people who lose an appeal never filed one. This guide lays out the stages, shows how to read the denial, and gives a checklist and a template for the letter.

The rules come from HealthCare.gov's pages on internal appeals and external review, the federal regulation on internal claims and appeals and external review (45 CFR 147.136), the Department of Labor claims procedure regulation (29 CFR 2560.503-1) and the regulation on grandfathered coverage (45 CFR 147.140), all checked on October 22, 2026. It is general information, not legal advice. This site covers prices and billing only, so nothing here says whether a treatment is necessary; the appeal turns on your plan's coverage criteria and the evidence your clinician provides.

Step one: read the denial for what it actually says

HealthCare.gov says insurers must tell you why they denied your claim or ended your coverage. For an employer group health plan, the Department of Labor rule goes further and lists what the notice must contain. The list is the checklist for reading your own letter.

Source: 29 CFR 2560.503-1(g)(1) and (g)(2), current eCFR text, checked October 22, 2026. Individual market and Marketplace plans must also follow the federal internal claims and appeals rules in 45 CFR 147.136; confirm what your plan's notice says.

The same regulation also gives you the right to request, free of charge, reasonable access to and copies of all documents, records and other information relevant to your claim. Use it. The claim file shows what the reviewer saw, what criteria were applied and whether the stated reason matches the record.

Why claims are denied, and how each type is usually fought

Not every denial is the same kind of problem, and the best response depends on the kind. Sort yours first.

Two points stand out. Many denials in the first row never need a formal appeal, and sending one can take longer than a corrected claim. And the medical necessity and experimental rows are the ones the external review rules were built for, because they turn on a judgment a second, independent clinician can make.

The stages and their clocks

The stages are the same for most plans, but the deadlines differ a little between the sources, so the table shows both the consumer summary and the regulation where they agree.

Individual-market plans that are not group health plans follow the internal appeal rules in 45 CFR 147.136(b)(3), and the Department of Labor regulation notes a minimum of 60 days to appeal for other employee benefit plans that are not group health plans. If your notice states a different deadline, follow the earlier of the two.

A worked calendar with invented dates

The dates below are hypothetical. They show how a typical sequence runs for a claim for a service already received.

The sequence takes seven months from denial to external decision, and that is when each deadline is met and nothing is extended. The lesson is practical: start gathering documents on the day the notice arrives, because a prompt appeal protects both the deadline and your position. For urgent situations, the expedited paths run in hours, not weeks, but whether a situation counts as urgent is for the plan and your clinician to decide.

What to put in the appeal packet

HealthCare.gov lists the minimum: the insurer's forms, or a letter with your name, claim number and health insurance ID number; any additional information you want considered, such as a letter from your doctor; copies of related documents, such as explanation of benefits forms and any form you signed to let someone else file for you; and notes from phone calls with the date, time, name and title of the person you spoke with, and what was discussed. The rest of this section builds on that list.

• The denial notice and the explanation of benefits. The reason code and the claim number tie your appeal to the record. See the guide to reading an explanation of benefits if the codes are unclear.
• The plan documents. The Summary of Benefits and Coverage or benefit booklet pages for the provision at issue.
• The claim file. The regulation entitles you to documents relevant to the claim, free of charge, on request. Ask for the criteria the plan applied.
• A letter from the clinician, where the denial turns on medical necessity. It should answer the plan's stated reason and criteria in the clinician's own words. This site does not describe what such a letter should say about care.
• Authorization records. The reference number, dates and names, if prior authorization is part of the story.
• Itemized bill and proof of payment. To show amounts, codes and anything you already paid.
• A call log. Date, time, name, title, what was said, and any reference number.
• A signed authorization, if a provider or advocate will file for you.

A letter template

A short letter that is specific beats a long one that is not. This is a template to adapt, not legal advice.

Send it the way the notice directs, and by a method that gives you proof of delivery. If the notice lists a fax number or a portal, use it and keep the confirmation. Call two weeks later to confirm the plan has it logged as an appeal, and write down who confirmed.

Your rights while the appeal is pending

Two protections matter. First, under the federal internal appeal rules, the plan or issuer must provide continued coverage pending the outcome of an appeal. The regulation points to the Department of Labor rule, under which benefits for an ongoing course of treatment cannot be reduced or terminated without advance notice and an opportunity for advance review. That protects coverage that was in place, such as a continuing course of services. It is not a right to start something new before approval.

Second, the Department of Labor rule requires that, for a group health plan, the review not afford deference to the initial denial and be conducted by an appropriate named fiduciary who is neither the person who made the initial decision nor that person's subordinate. When the denial rests on a medical judgment, including a finding that a treatment is experimental, investigational or not medically necessary, the fiduciary must consult a health care professional with appropriate training and experience in the field of medicine involved. You can ask the plan to identify the medical experts whose advice it obtained. These are the points that strengthen a case: you are entitled to a fresh review by someone else, and you can see what the plan relied on.

If you already received the service and a bill has arrived, ask the provider's billing office to place the account on hold while the appeal is pending, and keep the paper trail. If an account moves to a collector anyway, the guide to a medical bill in collections covers the written dispute that protects you.

External review: when the plan's final answer is no

HealthCare.gov describes external review as a review by an independent third party after the insurer's internal appeal, so that the insurer no longer has the final say. You file a written request within four months of the insurer's notice of final determination. It lists three kinds of denial that qualify: those involving medical judgment, where you or your provider disagree with the plan; those finding a treatment experimental or investigational; and coverage cancellations based on the insurer's claim that you gave false or incomplete information when applying.

If your state has an external review process that meets or exceeds federal standards, your insurer follows it. If not, HHS oversees external review for insurers in that state, and an insurer may use the HHS-administered process or contract with an independent review organization. The cost is capped: HealthCare.gov says there is no charge under the HHS-administered process, and that if the insurer uses an independent review organization or a state process you may be charged no more than $25 per review. The regulation says the independent reviewer's determination is binding on the plan or issuer, except to the extent other remedies are available under state or federal law, and it does not stop the plan from paying a claim voluntarily at any time. Under the federal process, the independent reviewer's eligibility notice tells you that you may submit additional information in writing within ten business days, and the reviewer must consider it.

Not every request gets to a full review: under the federal process the plan or issuer first has five business days to complete a preliminary review of whether the request is complete and the denial qualifies. A request should say plainly which category of denial it is and attach the denial letter. The questions that decide which route is yours: whether your plan is insured or self-insured, what the state offers, and which category fits.

Where these rules may not reach you

• Grandfathered plans. The regulation on grandfathered coverage says the ACA provisions on internal claims and appeals and external review, section 2719 of the Public Health Service Act, do not apply to grandfathered health plan coverage. To keep grandfathered status, a plan must include a statement in its summary of benefits that it believes it is grandfathered, with contact information for questions and complaints. Ask whether yours is, and ask what its own appeal procedure and deadlines are.
• Medicare. Original Medicare has its own appeal levels, started from the directions on the Medicare Summary Notice. Medicare Advantage has its own reconsideration process. See the Advance Beneficiary Notice guide for the Original Medicare case where a provider says Medicare may not pay.
• Medicaid. State Medicaid agencies run their own appeals and hearings. Contact the state agency for the process and deadlines.
• Self-funded employer plans. They follow the Department of Labor claims rule, and may be subject to a state external review process or the federal process depending on the facts. The plan documents say which.

In every case, the notice you received is the first place to look for the deadline. If it conflicts with a rule summarized here, treat the earlier date as the real deadline and ask for clarification in writing.

Help you can ask for

HealthCare.gov says your state's Consumer Assistance Program can file an appeal for you, and lists its general question line, 1-800-318-2596. Your state department of insurance is a usual place to ask about insured plans, and the Department of Labor's Employee Benefits Security Administration is a usual place to ask about employer plans. For a plan that is part of an employer benefit, the employer's human resources or benefits office can often tell you who administers appeals. Providers often have staff who handle appeals daily, so ask the billing office whether they will submit one with you.

Common mistakes

• Waiting for the bill. The appeal deadline runs from the denial notice, not from the date a bill arrives.
• Arguing with the wrong office. An appeal goes to the plan. A billing dispute goes to the provider. A corrected claim comes from the provider.
• Not answering the stated reason. The reviewer is looking at the letter's reasons. Respond to each.
• Sending nothing from the clinician when the denial is medical. The plan's criteria are medical, and so is the best response.
• Missing the four-month external review window, after the internal appeal ends.
• Giving up on a bill before the appeal is decided, or paying a collector while it is pending.

Appeals in brief

Where the deadlines and rights come from

• HealthCare.gov, Appealing a health plan decision, Internal appeals and External review. Checked October 22, 2026.
• eCFR, 29 CFR 2560.503-1, claims procedure: content of denial notices, appeal periods, reviewer independence, access to documents, urgent care timing. Checked October 22, 2026.
• eCFR, 45 CFR 147.136, internal claims and appeals and external review processes: continued coverage pending appeal, the four-month external review request window, expedited external review, binding decisions. Checked October 22, 2026.
• eCFR, 45 CFR 147.140, grandfathered health plan coverage. Checked October 22, 2026.

General information, not legal advice. Your plan documents, your denial notice and your state's rules control in a real case. Prices only on this site: no diagnosis or treatment advice.

While the appeal is pending, the practical risk is the bill. The guide to negotiating a hospital bill explains how to ask the hospital for a hold and a payment plan in writing without conceding the amount in dispute.