What to Do If an Insurance Company Denies Your Claim
What Does It Mean When an Insurance Company Denies Your Claim?
Key Takeaway: A denial means the insurer processed your provider's bill and refused to pay all or part of it. Your Explanation of Benefits shows the denied amount, reason code, and how to appeal. You may still receive a provider bill until the insurer reverses the decision.
When you ask what to do if an insurance company denies a claim, start by understanding what the insurer actually decided. Your provider submitted the claim with your member ID, diagnosis codes, and procedure codes. The insurance company's claims system or medical reviewer compared that submission to your plan benefits and returned a denial with a specific reason code.
Common remark codes include CO-50 for medical necessity, CO-197 for missing prior authorization, and CO-96 for non-covered services. Each code points to a different fix. Coding errors may be resolved when your provider resubmits the claim. Clinical denials require a member appeal with records that answer the insurer's stated rationale.
If you only received a phone call from the insurer, ask the company to put the decision in writing with the reason code and appeal instructions. For a broader overview of denial rights, see can insurance deny a claim.
How Should You Respond to the Insurer After a Denial?
Key Takeaway: Your first response to the insurance company should be organized, not emotional. Request the written denial, confirm the appeal deadline, and decide whether you need a corrected claim from your provider or a formal appeal packet sent to the insurer.
- Get the denial in writing. Ask for a formal adverse benefit determination with the reason code, policy section cited, and appeal instructions.
- Review your EOB line by line. Match each denied service to the remark or reason code on your Explanation of Benefits. See our guide on how to read an Explanation of Benefits.
- Mark the appeal deadline. The controlling date is on your denial notice, not a generic blog deadline.
- Request your claim file for ERISA plans. Employer plans must provide documents used in the denial decision under ERISA claims procedure rules.
- File your internal appeal with the insurer. Submit through the member portal or address listed on your denial letter. Keep proof of receipt.
- Request external review if the company upholds the denial. ACA marketplace plans must offer independent review after internal appeals under Healthcare.gov external review rules.
Which Denial Code From the Insurer Requires Which Fix?
Key Takeaway: The reason code on your denial letter tells you what the insurance company needs to see. Administrative errors usually start with your provider. Medical necessity, prior authorization, and step therapy denials need a written appeal with clinical documentation sent to the insurer or pharmacy benefit manager.
| Denial type | What the insurer is saying | First action |
|---|---|---|
| Medical necessity | Service or drug is not required for your diagnosis | Appeal with physician letter, clinical notes, and plan medical policy citations |
| Prior authorization | Service was performed without required pre-approval | Request retroactive authorization or appeal with urgency documentation. See how to appeal a prior authorization denial |
| Out-of-network | Provider is not in your plan network | Check emergency and facility-based protections under the No Surprises Act, then appeal with network access records if applicable |
| Coding or missing information | Claim data does not match records or is incomplete | Ask your provider to review and resubmit a corrected claim |
| Step therapy or formulary | Required cheaper drug trials were not documented | Appeal through your pharmacy benefit manager with prescriber records of prior drug trials |
Where Do You File an Appeal With Your Insurance Company?
Key Takeaway: Medical service denials go through your health plan's member portal or the mailing address on your denial letter. Prescription denials route through your pharmacy benefit manager, not your medical insurer. Confirm the submission channel on your notice before you send documents.
The insurance company that issued your card is not always the entity that processes every denial. Office visits, imaging, surgery, and hospital stays are appealed through your health plan portal. Medication denials are handled by your pharmacy benefit manager, whose name appears on your insurance card. Log into the portal listed on your denial letter and upload your appeal letter with all exhibits attached.
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How Do Appeal Deadlines Differ by Plan Type?
Key Takeaway: The controlling deadline is on your denial notice from the insurance company, not a blog post. ERISA employer plans, ACA marketplace plans, and Medicare use different clocks and forms. Missing the internal appeal deadline can end your case before external review is available.
| Plan type | Typical internal appeal pattern | External review or next level |
|---|---|---|
| ERISA employer plan | Federal claims procedure rules require a full and fair review. Many plans allow up to 180 days from the adverse benefit determination for the first appeal, but confirm the date on your notice. | Voluntary external review may be offered. Self-funded plans are overseen by the U.S. Department of Labor, not state insurance departments. |
| ACA marketplace plan | ACA Section 2719 requires internal appeals with timelines disclosed on your denial notice. File through the plan portal or address listed on the letter. | External review through an independent review organization is available after internal appeals for qualifying cases under ACA and state law. |
| Medicare | Original Medicare, Medicare Advantage, and Part D each use plan-specific notices. Medicare.gov lists the redetermination and Level 1 appeal clocks on your Medicare Summary Notice or plan denial. | Higher Medicare appeal levels continue through Medicare.gov. Do not use commercial ERISA deadlines for a Medicare case. |
For a deeper walkthrough of appeal windows, read how long you have to appeal a health insurance denial. Submit several days before the printed deadline so portal uploads or mail delivery do not cut your time short.
What Documents Should You Send the Insurance Company?
Key Takeaway: Appeals move when you answer the insurer's exact reason code with records a reviewer can verify. Build a packet the insurance company can open without calling you for missing pages.
- Denial letter, Explanation of Benefits, and claim number
- Insurance card, member ID, and Summary of Benefits and Coverage
- Medical records, test results, and operative reports when the denial is clinical
- Physician letter or letter of medical necessity tied to the plan medical policy
- Prior authorization history and pharmacy records for step therapy or formulary denials
Weak vs. Strong Language in an Insurer Appeal
Key Takeaway: Insurance company reviewers scan for the reason code, dates, and clinical support. Vague frustration without records rarely changes a denial. Specific citations to plan policy and attached evidence do.
| Weak statement | Strong statement |
|---|---|
| “My doctor ordered this test. Please pay.” | “Denial code CO-50 for lumbar MRI on 3/12/2026. Attached: six weeks of conservative therapy notes, physician letter, and imaging appropriateness criteria referenced in your medical policy section 4.2.” |
| “I need this medication.” | “Formulary exception denied for brand drug after documented failure of required step-therapy agents. Attached: pharmacy claims history and prescriber letter listing contraindications to the preferred alternatives.” |
| “This denial is unfair.” | “Claim #88421, denial dated 7/20/2026. I request the claim file under ERISA claims procedure rules and submit this Level 1 appeal with operative report and pathology results attached. Appeal deadline per notice: 1/16/2027.” |
What If the Insurance Company Upholds the Denial?
Key Takeaway: When internal appeal fails, qualifying ACA and state-regulated plans must allow external review through an independent reviewer. Self-funded ERISA plans follow federal rules and may offer voluntary external review. Medicare uses its own multi-level process on Medicare.gov.
Internal appeals are decided by the same insurance company that issued the denial, usually by a different unit. When that review upholds the decision, your denial letter should name how to request external review or the next appeal level. For step-by-step filing instructions, see our guide on how to request external review after an insurance denial.
If internal and external appeals fail on a fully insured plan, you may file a complaint with your state insurance department. Self-funded ERISA employer plans are generally overseen by the U.S. Department of Labor. For a related walkthrough focused on claim paperwork rather than insurer escalation, see what to do when an insurance claim is denied.
Frequently Asked Questions
Common questions about what to do when an insurance company denies your health claim.
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Disclaimer: This article is for educational purposes only and does not constitute medical or legal advice. AppealFlow is not an insurance company or law firm. Plan terms, appeal deadlines, and coverage rules vary. Review your denial notice and plan documents, and consult a licensed professional when appropriate. For emergencies, call 911. See our full disclaimer.