A denial letter looks like the end. It usually isn't.

Your next step depends on the U.S. policy in the file: health, Medicare, a workplace plan, auto, home, disability, or life. Those products do not share one federal appeal ladder. The notice in your hand names the deadline, the reason, and the address.

Already staring at a deadline you don't understand? Read the letter first. Use the path that matches your coverage.

Read the denial notice before you write anything

The notice should state why the claim was denied and how to appeal. It should also give you a deadline.

Call the number on the letter and ask for the reason and deadline in writing if the notice left them out. Keep the envelope if you still have it. The date you received the notice can matter later.

Don't toss the Explanation of Benefits, the claim number, or your policy booklet. You'll need all three when you write.

What to do in the first week

1. Copy the claim number, the stated reason, and the appeal deadline onto one page.
2. Request the claim file and the policy language the insurer used to deny the bill.
3. Gather records that answer that stated reason, not a stack of unrelated paper.
4. Ask your doctor, body shop, or contractor for a short letter tied to that reason.
5. Send the appeal the way the notice requires, and keep proof of delivery.

A coding mistake is sometimes a resubmit, not an appeal. Ask the provider's billing office whether they can correct the claim first.

How to appeal a denied health insurance claim

Non-grandfathered health plans, including marketplace coverage, start with an internal appeal. You ask the same insurer to look again. Attach new evidence. Send copies and keep the originals.

Urgent medical situations run on a shorter clock. HealthCare.gov says the plan must decide as quickly as your condition requires, and at least within 4 business days after it gets an urgent request. They can tell you by phone. Written notice has to follow within 48 hours.

Turns out a lot of people never log the calls. Write the day, time, name, and title of anyone you spoke with, plus what they said.

The plan can still deny the claim after that internal review, and many consumers can then request an external review, where an independent reviewer takes the file. Some states run that process themselves.

HHS administers a federal external review for non-grandfathered plans when your state does not run one or your plan uses the federal path. It applies to policies first sold or significantly changed after March 23, 2010.

Grandfathered plans may not have this ACA external-review right.

The denial notice should say whether you can use it. A state process may charge a fee. HealthCare.gov says that fee, if allowed, can't be more than $25 per external review.

Urgent cases sometimes let you file the internal appeal and the external review together. Look for that instruction on the letter.

Medicare denials use a separate ladder

Medicare does not use the marketplace external-review form. Original Medicare fee-for-service appeals generally climb these levels:

1. Redetermination by a Medicare Administrative Contractor
2. Reconsideration by a Qualified Independent Contractor
3. A decision by the Office of Medicare Hearings and Appeals
4. Review by the Medicare Appeals Council
5. Federal court

Medicare Advantage and other Medicare parts often start with the health plan, so the first envelope you get may come from the insurer rather than a Medicare contractor. Early level names change by program. Later levels still go through an independent organization, OMHA, the Appeals Council, and court.

The Medicare notice names the level you are on and how to file. Follow that paper, not a generic checklist. You can appoint a representative with form CMS-1696 or a written appointment that includes the elements in 42 CFR 405.910.

ERISA clocks for workplace health and disability

Private employer health and disability plans often follow federal ERISA claim procedures. Those rules set clocks. They do not decide the medical dispute for you.

The Department of Labor lists these windows for the original group health claim, before an appeal starts:

The plan generally decides within 48 hours after you send missing pieces on an urgent claim, or after the time to send them runs out. Pre-service claims get up to 15 more days after you supply what was missing.

Appeals have separate clocks. DOL's example: a plan with one appeal level must review a pre-service appeal in a reasonable period, no later than 30 days after it receives the appeal. Urgent claims can be filed by phone. Put the same request in writing the same day.

Workplace disability denials usually stay inside the plan's ERISA process. They do not automatically get the ACA external review used for many individual health policies.

Auto, home, and other non-health denials

Thing is, auto and homeowners claims do not plug into that health-insurance external review. They live in the contract and in state insurance oversight.

Fault, photos, police reports, and a second shop bid do more work in an auto fight than a medical-necessity letter ever would, and home claims usually turn on photos, a contractor estimate, and whatever the policy says about the cause of loss, while life or individual disability disputes hang on the contract's own definitions rather than a federal form, which is why people get stuck treating every denial like a health-plan external review when it isn't.

Your state insurance department takes complaints about claim handling. File one if the insurer goes silent; a complaint does not guarantee payment.

What to put in the appeal letter

A medical-necessity letter will not fix a late filing, and a police report will not fix a coding error. Answer the reason they gave.

Name the claim, quote the denial, point to the policy language, and attach the proof.

[Your name]
[Policy number and claim number]
[Date]

Appeals Department
[Insurer name and address from the denial letter]

Re: Appeal of claim [claim number], denied on [date]

I am appealing the denial of this claim. The denial letter dated [date] says [quote the reason].

That reason does not match the record because:
1. [Fact plus attachment, such as a physician letter dated ...]
2. [Policy section or report that supports coverage]

Please reverse the denial and process payment of [amount or remaining balance].

Enclosed: [list each attachment]
I can be reached at [phone] and [email].

[Signature]
[Printed name]

Use certified mail or the portal named in the notice. Save the receipt.

To be honest, the letter does not need legal phrasing, it needs the claim number and the deadline and evidence that talks back to the denial reason, even if you repeat one fact in the letter and again in the enclosure list because you want the reviewer to trip over it twice.

When the insurer still says no

External review, where it applies, is the independent look. For the HHS-run federal process, that decision is final inside that process. There is no extra federal external-review round after it.

Property and auto denials often go next to the state insurance department. Employer-plan procedure questions can go to the Labor Department's EBSA. Large unpaid bills are the point where some people call a consumer or benefits lawyer. This is practical information, not legal advice.

Circle the deadline on the denial letter, grab the one record that answers the stated reason, and send the appeal the notice describes. Do it while the window is still open.