A denied, delayed, or underpaid insurance claim usually starts with a dated letter that names your policy, claim number, and the decision you want changed. You don't need a court form.
Have you already gotten a denial that barely explains the reason?
That notice is your map, not the last word. This page is for U.S. consumers, it is not legal advice, and auto, home, and health files do not follow one shared script.
What a complaint letter actually does
You send the letter to the claims department so the company has to open its own file again and answer you in writing.
That is the first move. For many auto and property disputes, that internal review is the main path before a state insurance department complaint. Health coverage often adds a second, independent review after the plan's own appeal.
The letter should state the facts, point to evidence or policy language the denial skipped, and ask for a specific action by a date you name. It will not invent coverage the policy never sold.
Thing is, a vague rant about rude service rarely moves an adjuster, so quote their reason and attach the estimate, report, or bill that cuts against it.
A sample letter you can copy and edit
Fill every bracket with your real numbers and keep the wording specific.
[Your full name]
[Street address]
[City, State ZIP]
[Email]
[Phone]
[Date]
[Insurance company name]
[Claims department]
[Company address]
[City, State ZIP]
Re: Formal appeal of claim [claim number], policy [policy number]
Dear Claims Supervisor:
I am writing to appeal the [denial / delay / underpayment] of claim [claim number], submitted on [date]. Your letter dated [denial date] states the reason as "[quote the insurer's wording]."
On [incident date], [one or two factual sentences about what happened]. I submitted [list of documents]. Those materials show [one sentence tying the evidence to coverage].
I ask you to [pay $X / reverse the denial / issue a written explanation of remaining delays] within 30 days of receiving this letter. If I do not receive a written decision, I will file a complaint with my state insurance department.
Enclosed copies: [list]. Please confirm receipt in writing.
Sincerely,
[Your name]Mail a paper copy and keep one. Certified mail with a return receipt is the usual way to prove the company got it.
Auto, home, and health are not the same fight
An auto underpayment fight is often about numbers on estimates. You attach an independent shop figure, photos, and the police report if one exists, then you ask for a line-by-line comparison instead of a speech about fairness.
Homeowners delays are usually about time, so cite the report date and who walked the property.
Health is the outlier because federal appeal rights can kick in after the plan's own review, at least for many non-grandfathered plans. Your denial letter should say how to appeal, and the U.S. Department of Labor's claim-filing guidance walks through how group health claims are timed, including urgent claims the plan must decide as soon as possible and no later than 72 hours after it receives them.
To be honest, copying a "bad faith" threat into every first letter is a habit people pick up online, it often adds heat without adding proof, so leave those labels out.
Health coverage: internal appeal, then external review
If a health plan still says no after its internal appeal, many consumers can request an independent external review under the Affordable Care Act, so don't skip that second step.
See HealthCare.gov's internal appeals page and the external review explainer. You may request an internal appeal and an external review at the same time.
For urgent care, a final decision has to come as quickly as the medical condition requires, and at least within four business days after the request is received.
That answer can start on the phone. Written notice must follow within 48 hours.
Some states run their own external review, and if a state's process does not meet federal standards, HHS uses a federal process with MAXIMUS; the HHS fact sheet on federal external review says a MAXIMUS decision is final under that process.
Grandfathered plans, often those in place without major changes since March 23, 2010, may sit outside these extra steps. Read the denial notice. HealthCare.gov also says that if a fee is charged for an external review, it cannot be more than $25.
Keep your originals and send copies, and jot down the day, time, name, and title of anyone you spoke with.
What to gather before you hit send
Pull the file together before you write. Missing a claim number wastes a week.
- Denial or delay letter, quoted word for word
- Policy and claim numbers, plus the coverage page you are relying on
- Photos, police or incident reports, repair estimates, bills, or explanations of benefits
- A call log with dates
- The appeals address printed on the denial, which may not be headquarters
If the plan said "not medically necessary," ask for the clinical criteria it used. If it said information was missing, ask exactly which documents and where to resend them.
Internal review vs. a state insurance complaint
| Path | What it is | When people use it |
|---|---|---|
| Company appeal letter | The insurer reviews its own decision | First step for almost every claim type |
| State insurance department complaint | Your state regulator asks the company to respond | After silence, a thin explanation, or a stall |
| External review (many non-grandfathered health plans) | An independent reviewer decides | After the internal appeal, or at the same time if allowed |
Turns out many files move once a department of insurance complaint number is sitting on them. That still depends on the policy language and the proof you attached.
A state complaint is usually free, it's not a lawsuit, and the regulator can make the company answer without always ordering a check.
After the company still says no
Write a short follow-up that attaches the first letter and the delivery receipt, then file with your state insurance department using its online form if it has one.
Request external review if a health internal appeal already failed. Group health and disability clocks are also summarized in the Department of Labor claims publication, and the federal health appeal rule is in 45 CFR 147.136.
Print the packet tonight. Check the deadline on the denial letter. If it's close, send what you have and say more records will follow.