Health Insurance Claim Denied? What to Do Next

You opened the mail and found those dreaded words: claim denied. Now you are wondering, health insurance claim denied what next? The answer is not to panic and not to pay the bill without a fight. A large share of appealed claim denials are eventually overturned, which means the odds are better than most people assume — but only if you act inside the deadlines. This is general information, not legal or insurance advice; verify the details on your own denial letter, which controls your specific rights and timelines.

Every year, millions of Americans face insurance claim denials. Analyses by KFF (the Kaiser Family Foundation) have found that insurers in ACA marketplace plans deny a substantial share of in-network claims — on the order of roughly one in five in the years studied — yet only a tiny fraction of denials are ever appealed. Many denials are based on correctable errors or questionable medical-necessity determinations. This guide gives you a clear action plan for what to do immediately after a denial and how to navigate the appeals process step by step.

Step 1: Read and Understand the Denial

Your Explanation of Benefits (EOB) or denial letter is the single most important document in this process. It tells you exactly why the claim was denied, which policy provision the insurer relied on, and what your appeal rights and deadlines are. Do not skim it. Read every line, and note the specific denial or “reason” codes.

Denials generally fall into a few categories: the service was not covered under your plan, the service was deemed not medically necessary, prior authorization was not obtained, the provider was out of network, coverage or eligibility was not recognized, or there was a billing or coding error. The category determines your next steps and the type of evidence you need to gather.

Pay special attention to the appeal deadline. Under ACA rules, you generally have 180 days (about six months) from the date you receive the denial to file an internal appeal, though some plans set details differently — so check your denial letter deadlines and write the date down immediately.

Step 2: Check for Administrative Errors

A surprising number of claim denials are caused by simple mistakes: a wrong diagnosis code, an incorrect procedure code, a misspelled name, a transposed policy number, or a claim sent to the wrong plan. Call your healthcare provider’s billing department and ask them to review the claim for errors.

If an error is found, your provider can submit a corrected claim directly to the insurer. This is often faster than a formal appeal and can resolve the issue within a few weeks. If the denial was your insurer’s error — such as failing to recognize your coverage or applying the wrong benefit — call member services and request that the claim be reprocessed. Keep a log of every call: the date, the representative’s name, and any reference number they give you.

Step 3: Contact Your Doctor

Your treating physician is a critical ally when your health insurance claim denied what next decision-making begins. If the denial was based on medical necessity, ask your doctor to write a letter of medical necessity explaining why the treatment was required for your specific condition. The letter should include your diagnosis, symptoms, prior treatments attempted and their results, and the clinical rationale for the denied service, ideally citing relevant clinical guidelines.

Many insurers also offer a peer-to-peer review process, where your doctor can speak directly with the insurer’s medical reviewer. This conversation can sometimes resolve disputes without a formal written appeal, and your doctor may be more persuasive speaking clinician-to-clinician than any letter could be.

Step 4: File an Internal Appeal

If the denial cannot be resolved through a corrected claim or a phone call, file a formal internal appeal in writing. Your appeal letter should include your personal and policy information, the claim number, the date of service, the stated reason for denial, and your argument for why the claim should be covered.

Attach all supporting documentation: medical records, your doctor’s letter of medical necessity, relevant clinical guidelines, and the applicable pages from your policy or Summary of Benefits and Coverage. Send everything by certified mail with return receipt (or through the insurer’s official portal with confirmation) so you have proof of timely submission. For guidance on structuring your letter, see our article on how to write an appeal letter.

Under current federal rules, the insurer must generally decide your internal appeal within 15 days for a pre-service claim (such as prior authorization for treatment you have not yet received), 30 days for a post-service claim (services you already received), and 72 hours for urgent care. If you request an expedited appeal for an urgent situation, a final decision can be required as quickly as within a few business days. Confirm the exact timeframes in your plan documents, since plans can be more generous than the federal minimums.

Step 5: Escalate to External Review

If your internal appeal is denied, you have the right under the ACA to request an external review by an Independent Review Organization (IRO) — a review by medical professionals who have no connection to your insurance company. Critically, their decision is binding: your insurer is required by law to accept it.

You generally have four months from the date of the final internal appeal denial to request an external review. A standard external review is typically decided within 45 days of the request, while an expedited review for an urgent situation can be decided within 72 hours or less. The IRO evaluates your medical records, clinical guidelines, and the insurer’s rationale, then issues its decision. External reviews overturn a meaningful share of denials, making this a step well worth pursuing.

Step 6: Know Your No Surprises Act Protections

Not every large bill is a normal denial — some are surprise bills. The federal No Surprises Act protects you from many surprise out-of-network charges, including most emergency care and many situations where an out-of-network provider treats you at an in-network facility (for example, an out-of-network anesthesiologist during in-network surgery). In these cases you generally cannot be balance-billed beyond your normal in-network cost-sharing, and the provider and insurer are supposed to resolve the balance between themselves.

If you receive a bill that looks like a surprise out-of-network charge, do not assume it is valid. You can dispute it, and the Centers for Medicare & Medicaid Services (CMS) operates a No Surprises Help Desk for consumers. This is separate from — and in addition to — the standard appeals process above.

Step 7: File a Complaint With Your State

Your state insurance department regulates insurers operating in your state and can investigate complaints about unfair denial practices. Filing a complaint does not replace the formal appeals process, but it creates an additional layer of accountability, and some state departments actively mediate between consumers and insurers.

The National Association of Insurance Commissioners (NAIC) provides a directory of state insurance departments (often called the Department of Insurance, or DOI). Many states also have Consumer Assistance Programs (CAPs) funded under the ACA that offer free help navigating insurance disputes and appeals.

Special Considerations for Employer-Sponsored Plans

If you get your insurance through your employer, your plan may be governed by ERISA. ERISA plans have specific appeal requirements, including mandatory timelines and the right to a full and fair review. One critical difference is that if you exhaust your ERISA administrative appeals, your next step is generally a federal lawsuit rather than a state external review (though some self-funded plans voluntarily offer external review).

Under ERISA, the administrative record you build during the appeal is typically the only evidence a court will later consider. That makes every document, letter, and medical record you submit during the appeal matter enormously — submit everything relevant before the administrative process closes. The U.S. Department of Labor’s Employee Benefits Security Administration oversees ERISA compliance and offers resources for claimants.

When to Get Professional Help

You do not need a lawyer for every denied claim, but certain situations warrant professional assistance. If the claim involves a large dollar amount, a complex medical-necessity dispute, an ERISA-governed plan, or a pattern of repeated denials, an attorney or patient advocate can significantly improve your chances.

Many healthcare attorneys offer free consultations, and some work on contingency, meaning they are paid only if you win. Patient advocates and medical-billing specialists can also help you navigate the process, spot errors, and build a stronger case. The investment in professional help often pays for itself many times over. A closely related read is our guide on the appeal letter format, which pairs with this one.

Frequently Asked Questions

Should I pay the bill while I appeal?

Generally, you should not pay a disputed bill while the appeal is pending, since payment can sometimes be treated as accepting the denial. However, watch for payment deadlines that could send the bill to collections. Contact the provider’s billing department, explain that you are appealing the insurance denial, and ask them to pause collection efforts during the active appeal — most will.

How long does the entire appeals process take?

An internal appeal is typically decided within 15 to 30 days (72 hours for urgent cases). If you escalate to external review, a standard review adds up to about 45 more days. Start to finish, a routine dispute can take a few months, while urgent appeals are decided far faster — within 72 hours at each stage.

Can I appeal a claim denied a long time ago?

Appeal deadlines are strict; most plans require you to file the internal appeal within 180 days of the denial. If you missed the deadline, your options are limited, but some states and plans allow exceptions for good cause. Contact your state insurance department or Consumer Assistance Program to explore any remaining options.

What if the denial was for a service I already received?

You can and should appeal post-service denials. The process is the same as for pre-service denials, though the insurer generally has 30 days rather than 15 to decide. If the appeal succeeds, the insurer pays the claim and you should owe the provider nothing beyond your normal cost-sharing.

Is a surprise out-of-network bill the same as a denial?

Not exactly. A surprise bill often stems from out-of-network billing rather than a coverage denial, and the No Surprises Act may cap what you owe to your in-network cost-sharing. If you think a bill is a protected surprise charge, dispute it and contact the CMS No Surprises Help Desk in addition to any regular appeal.

Do Not Give Up

When your health insurance claim denied what next question arises, remember that a denial is not the end — it is the start of a process designed to give you a fair hearing. Check your denial letter deadlines, follow each step methodically, document everything, and do not hesitate to escalate to external review or your state regulator. For more resources, explore our healthcare policy guide and our overview of healthcare costs.

Sources

• HealthCare.gov (CMS) — Appealing a health plan decision: internal appeals (file within 180 days; insurer decisions within 15 days pre-service, 30 days post-service, 72 hours urgent; expedited final decision as fast as a few business days) and external review (request within 4 months; decided within 45 days standard or 72 hours expedited; binding on the insurer)
• Centers for Medicare & Medicaid Services (CMS) — No Surprises Act consumer protections against surprise out-of-network balance billing
• U.S. Department of Labor, Employee Benefits Security Administration (EBSA) — ERISA claims-and-appeals rules for employer-sponsored plans
• KFF (Kaiser Family Foundation) — analyses of ACA marketplace claim denials and appeal rates
• National Association of Insurance Commissioners (NAIC) — directory of state insurance departments; ACA-funded Consumer Assistance Programs