A Health Insurance Claim Was Denied. Here Is How to Challenge It
A health insurance denial can look like a final bill, especially when a hospital or doctor starts asking for payment. But a rejected claim may reflect missing information, a coding problem or a coverage decision that you can challenge. Your first job is to find out which one it is. An explanation of benefits, or EOB, describes how your insurer processed a claim; it is not itself a bill.
For people navigating a denial in 2026, there is no single appeal process that fits every health plan. Employer plans, individual policies, Medicare and Medicaid follow different rules, and state protections do not apply equally to all of them. Start with the denial notice and plan documents, protect the earliest deadline you find, and keep a written record. You do not need to argue everything at once: identify the stated reason, then assemble evidence that directly answers it.
1. Find out whether the problem is billing or coverage
Compare the EOB with the provider’s itemized bill. Match the patient, service date, provider, procedure and amount. Look for a denial or adjustment code, then read its explanation. A duplicate claim or incorrect member number usually calls for correction by the billing office. A finding that treatment was not medically necessary usually calls for an appeal supported by clinical evidence.
A charge applied to your deductible is generally not a denial: the plan may have covered the service while assigning the allowed amount to you. Likewise, the provider’s original charge is not automatically what you owe. Ask the insurer whether its network contract makes any denied amount the provider’s responsibility. Do not assume a billing office can transfer its own filing mistake to you.
Call both sides when the paperwork conflicts. Ask the provider whether it submitted a corrected claim and ask the insurer whether that claim arrived. Get reference numbers. A promise to reprocess a claim is useful, but it does not necessarily extend your appeal deadline.
| What the paperwork says | Likely next step | What to verify |
|---|---|---|
| Wrong member information or duplicate claim | Ask the provider to correct or clarify the claim | Corrected submission date and claim number |
| Missing referral or authorization | Check records and plan requirements | Whether approval existed or an exception applies |
| Not medically necessary | Prepare a clinical appeal | Criteria used and supporting medical records |
| Service excluded from benefits | Compare the denial with plan language | Exact exclusion and whether it fits the service |
| Amount assigned to deductible | Check benefit accounting | Allowed amount and remaining deductible |
2. Identify the plan and write down every deadline
Ask what kind of coverage you have, not just which company’s name appears on the card. An employer may buy insurance or pay claims itself through a self-funded plan administered by an insurer. That distinction affects the regulator and external-review route. Request the summary plan description for employer coverage, or the policy or evidence of coverage for an individual plan.
Many employer group plans subject to federal benefit rules, and non-grandfathered plans subject to Affordable Care Act appeal protections, allow at least 180 days to request an internal appeal. Do not treat that as a universal deadline. Medicare, Medicaid and other coverage can use different clocks. Some notices also distinguish the time to appeal from a shorter deadline to keep benefits continuing during review.
Copy the actual filing instructions into your calendar, including the submission address and required delivery method. If documents are missing, ask how to submit a timely appeal and supplement it. Never assume a phone complaint, a provider’s appeal or an insurance department complaint preserves your personal appeal rights.
- Record when you received the notice and keep the envelope or electronic notification.
- Ask whether the plan requires one or two internal appeal levels.
- Confirm whether the deadline means received by or sent by that date.
- Track corrected claims and formal appeals separately.
3. Build a file that answers the reason for denial
Request the complete denial notice if you received only an abbreviated EOB. It should explain the reason and applicable appeal rights. Ask for the specific benefit provision, medical-necessity guideline or other rule used. Under applicable federal appeal rules, you can request relevant claim documents without charge. That is more useful than guessing which standard the reviewer applied.
Collect records selectively. For a medical-necessity denial, ask the treating clinician for a letter connecting your condition and treatment to the plan’s criteria. Useful details include symptoms, previous treatments that failed, contraindications and why a covered alternative would not work. For an authorization dispute, the most important evidence may instead be a dated approval, referral or submission confirmation.
Keep copies rather than sending irreplaceable originals. If someone will act for you, ask the plan for its authorized-representative form; permission to discuss your account may not authorize an appeal. Send sensitive records through the plan’s designated secure channel.
- Denial notice, EOB, itemized bill and relevant benefit pages.
- Medical records and a targeted clinician’s supporting letter.
- Referral, authorization and network-status evidence, when relevant.
- A dated contact log with names and reference numbers.
- Copies of submissions and proof that the plan received them.
4. File a focused internal appeal
Use the plan’s form if required, but attach a clear explanation when the form leaves too little space. Identify the member, claim number, service date and provider. State that you are requesting a formal internal appeal and specify the outcome you want: payment, authorization or reversal of the particular denial. Follow the notice’s submission instructions rather than mailing everything to a general customer-service address.
Organize the appeal around the denial, not the size of the bill. You might explain that the plan denied a service for missing authorization, then identify the authorization number and attach confirmation. For medical necessity, point to the relevant criteria and the clinician’s explanation. If a benefit exclusion was misapplied, quote the relevant policy language and explain why the service falls outside that exclusion.
Number attachments and keep the full packet. Request written acknowledgment and the expected decision date. Ask the provider whether a peer-to-peer discussion is available, but verify whether that discussion counts as an appeal. Often it is a separate step. Before any deadline passes, confirm that the plan logged your submission as an appeal, not merely an inquiry.
5. Match the review speed to the medical situation
Appeal timing depends partly on whether you are seeking approval before treatment, disputing a bill after treatment or facing an urgent medical situation. Under common federal private-plan rules, internal appeal decisions generally must arrive within 30 days for pre-service appeals and 60 days for post-service appeals. Plans with two mandatory appeal levels can divide the applicable time between levels. Other programs have their own schedules.
For qualifying urgent-care appeals under those rules, the decision must come as quickly as the medical situation requires, generally no later than 72 hours. Urgency is about the risk from waiting, not simply a large balance or an approaching payment date. Ask your clinician to explain if delay could seriously jeopardize your health or ability to regain function, or cause severe pain that cannot be adequately managed.
Call the expedited-review number in the notice and ask what clinical documentation is needed. In qualifying situations, expedited external review may be available alongside an urgent internal appeal. If ongoing treatment is being reduced or stopped, ask immediately about continued-coverage rights and their deadlines. Do not postpone emergency care while sorting out an appeal.
6. Check whether independent external review is available
After a final internal denial, eligible claims can go to independent external review. This is not simply another customer-service reconsideration. The route depends on the plan and the dispute. Fully insured coverage often uses a state process; many self-funded employer plans use a federal process. Certain failures to follow required appeal procedures can also permit moving beyond internal review.
External review commonly covers denials involving medical judgment, including medical necessity and experimental treatment, and certain other decisions protected by law. It is not available for every disagreement over billing or an excluded benefit. Certain No Surprises Act determinations also qualify under applicable rules. Ask which category covers your denial rather than assuming every final denial is eligible.
Under the federal external-review process, requests generally must be filed within four months after receipt of the relevant denial notice. Standard decisions generally take no more than 45 days; qualifying expedited decisions must come as quickly as necessary, within 72 hours. State processes can differ, so follow the applicable notice. Medicare and Medicaid have separate appeal systems; use their program-specific instructions rather than a commercial plan’s external-review form.
7. Protect yourself while the dispute is pending
Tell the provider you are challenging the denial and request a written hold on billing or collections. An appeal does not automatically freeze the account. Ask about financial assistance if the balance threatens your budget, but do not assume you must accept the debt to seek help. If the dispute involves surprise billing, check federal and state protections before paying an out-of-network balance.
Escalate stalled cases to the right place. Your state insurance department can help identify its jurisdiction and applicable review process. For many private-sector employer plans, the Labor Department’s Employee Benefits Security Administration can explain federal rights. Medicare beneficiaries can seek free counseling through their State Health Insurance Assistance Program. Save every final decision: it should explain further rights, and substantial unresolved claims may warrant advice from an employee-benefits or insurance attorney.
Check your current plan documents and denial notice for controlling terms and deadlines, and consult a qualified benefits adviser or attorney when necessary.
AI Assistance Used — AI assistance was used in researching and drafting this article. It was reviewed, edited, and fact-checked by Jordan Singh before publication.