My health insurer (for example UnitedHealthcare) denied my in-network hospital claim. How do I appeal?

Health insuranceAppealChecked Nov 5, 2026

From K.Actuary, founded by Sangmin Kwon, ASA · sources checked 2026-11-05 · Source: eCFR · 29 CFR 2560.503-1 · § 2560.503-1(h)(3)(i) View original ↗

In short

Read the denial reason on your Explanation of Benefits (EOB).
You usually have 180 days to appeal. Ask for your claim papers for free.
If the appeal fails, you may ask for outside review within 4 months.

What this means

Federal rules set the basic appeal rights, whatever the insurer's name. If your plan comes through a job, the plan must give you at least 180 days after you get the denial to appeal [1]. If you bought it on the marketplace, HealthCare.gov also says 180 days (6 months) [2]. You can ask for free copies of all papers the plan used for your claim [3].

For a marketplace plan, the plan must finish the appeal within 60 days for care you already got [2]. If it still says no, you can ask for an outside (external) review in writing within 4 months after the final denial. A standard review is decided within 45 days. Your insurer must accept the reviewer's decision [4].

Since the hospital is in network, also ask the hospital's billing office to help. They may need to send records or fix a code.

Your next step

Find the denial reason code on your EOB. Ask the plan in writing for your claim file, then send your appeal with the hospital's records.

Deadline: at least 180 days after you get the denial — use the date in your denial letter.

Check it yourself

Your denial letter says whether your plan is job-based or individual and where to send the appeal. UnitedHealthcare's own appeal forms and online steps were not checked here — "Don't know yet"; use the address on your denial letter. Whether an in-network hospital may bill you for a denied claim depends on its contract with the plan — "Don't know yet" from these sources.

Where this comes from (4)

[1] eCFR · 29 CFR 2560.503-1 · § 2560.503-1(h)(3)(i) · checked 2026-11-05
( i ) Provide claimants at least 180 days following receipt of a notification of an adverse benefit determination within which to appeal the determination;
[2] HealthCare.gov · Internal appeals · checked 2026-11-05
You must file your internal appeal within 180 days (6 months) of receiving notice that your claim was denied. … Your internal appeals must be completed within 60 days if your appeal is for a service you've already received.
[3] eCFR · 29 CFR 2560.503-1 · § 2560.503-1(h)(2)(iii) · checked 2026-11-05
Provide that a claimant shall be provided, upon request and free of charge, reasonable access to, and copies of, all documents, records, and other information relevant to the claimant's claim for benefits.
[4] HealthCare.gov · External Review · checked 2026-11-05
You must file a written request for an external review within 4 months after the date you receive a notice or final determination from your insurer that your claim has been denied. External reviewer issues a final decision: An external review either upholds your insurer's decision or decides in your favor. Your insurer is required by law to accept the external reviewer's decision. … Standard external reviews are deci…

How we found this

We matched your question to 4 official sources, quoted the exact lines, and re-checked each quote against its source on 2026-11-05.

What we don’t know yet

Your own plan or notice may say something different. If your letter cites another rule, send it and we will look again.

Every answer is checked against the official rule it quotes.

Information only — not legal advice. Your plan, insurer or agency decides.

This answer quotes the official sources listed above, with the date we checked them. Your own policy, notice and state rules control. We are not your lawyer or your insurer. We don’t file, argue or negotiate claims for you — you send any letter or form yourself.

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