How long does an appeal letter need to be?

Shorter than most people fear. The parts that have to be there are identifiers, a verbatim quote of the denial reason, one sentence naming what you dispute, a numbered answer to each element of the standard the plan applied, a numbered list of enclosures, the decision you are asking for, and the date. On one or two pages that is comfortable. Length is not what makes an appeal work; the enclosure list is. The reviewer is working to a fixed clock — 30 days on a pre-service claim, 60 on a post-service claim where the plan has a single appeal level (29 CFR 2560.503-1(i)(2)(ii) and (iii)(A), read 7 September 2026) — so build the letter to be checked rather than read twice: every assertion points at a numbered exhibit, and every exhibit points back at a criterion.

Do I have to use my insurer's appeal form, or can I send my own letter?

Check the denial notice, because plans are required to describe how to initiate an appeal (45 CFR 147.136(b)(2)(ii)(E)(4)). Many plans publish a form. A form, though, is a cover sheet with boxes, and the boxes are rarely large enough for what you actually need to say. The usual arrangement is both: the plan's form filled out completely, with your letter attached as the first enclosure and the form's narrative box saying 'see attached letter dated [date].' Nothing in the federal claims rule conditions your right to a full and fair review on using a particular piece of stationery, but a plan is allowed to have reasonable filing procedures, so follow the ones it published.

Should my doctor write the appeal instead of me?

They are different documents and you generally want both. A plan cannot bar an authorized representative from acting for you (29 CFR 2560.503-1(b)(4)), and for a claim involving urgent care a health care professional with knowledge of your condition must be permitted to act as your representative. But a provider letter works best as evidence rather than as the appeal itself: it is the document that states clinical findings, dates, and treatment history against the plan's own criteria. Your letter is the one that names the claim, quotes the denial, lists the enclosures, and asks for a specific decision. Plans usually require a signed authorization before they will deal with a representative, so ask which form they want before assuming a letter alone is enough.

What happens if the insurer never answers my appeal?

Silence is a lever rather than a dead end. Federal timeframes for a decision on review run 72 hours for a claim involving urgent care, 30 days for a pre-service claim, and 60 days for a post-service claim where the plan has a single appeal level (29 CFR 2560.503-1(i)(2)(i) through (iii), read 7 September 2026). Separately, when a non-grandfathered plan or issuer fails to strictly adhere to the internal appeal requirements, the claimant is deemed to have exhausted the internal process and may initiate external review or pursue remedies under ERISA section 502(a) (45 CFR 147.136(b)(2)(ii)(F)(1)). There is a narrow exception for de minimis violations, and you may request a written explanation of the violation, which the plan must provide within 10 days.

How to Write an Insurance Appeal Letter Without a Template

Your appeal goes into a file, and then somebody who has never seen your claim opens that file and reads it from the top. That stranger, not the person who turned you down, decides what happens next. Nearly every choice about what belongs in the letter follows from that one fact.

Federal regulation is the reason it works that way. A group health plan's appeal has to be decided by a named fiduciary who is neither the person who denied the claim nor that person's subordinate, and who gives the first decision no deference at all (29 CFR 2560.503-1(h)(3)(ii)). The review must also take into account everything you submit, "without regard to whether such information was submitted or considered in the initial benefit determination" ((h)(2)(iv)). Put those two paragraphs together and the letter has a job description: it is the mechanism that puts new material into the record, and the map that tells a stranger where in the file to look.

Regulatory text on this page was read in the eCFR on 7 September 2026, when it reported title 29 and title 45 as current as of 3 September 2026 and last amended 31 August 2026. Rules get amended; the section links go to the live text.

Who opens the envelope at the other end

The reviewer is holding a file. Your claim, the codes on it, the plan's own criteria document, and whatever the first adjudicator wrote. What that person does not have is anything you know and have not yet sent.

The rules narrow that audience further. If the denial turns on a medical judgment — experimental, investigational, not medically necessary or not appropriate — the fiduciary has to consult a health care professional with training and experience in the relevant field, and it cannot be the professional consulted the first time or that person's subordinate ((h)(3)(iii) and (v)). The plan must also be able to identify the medical or vocational experts whose advice it obtained, whether or not it relied on that advice ((h)(3)(iv)).

The practical consequence is unglamorous: write for someone with no memory of your case. Background that felt redundant on the phone is not redundant on paper. The clinical history, the alternatives already tried, the dates — none of it is in the reviewer's head, and a call you had in March is not in the file unless you put it there.

The identifier block is not filler

The top of the letter exists so the document cannot be misfiled, and so nobody has to guess which of your claims you mean. Twelve lines of it beat any amount of eloquence further down.

Line	What to write	Where to find it
Document type	"First-level internal appeal" or "Second-level internal appeal"	The denial notice describes which levels exist
Patient name and date of birth	As printed on the insurance card	Card
Subscriber name, if different	The employee or policyholder	Card
Member or policy ID, group number	Exactly as printed, letters included	Card
Claim number	One per claim; list all if the same reason denied several	EOB or denial notice
Date or dates of service	The service date, not the billing date	EOB
Provider or facility name	The one that billed, which may not be the one you saw	EOB
Billed amount and denied amount	Both, where they differ	EOB
Denial code and its meaning	The code and the plain-language meaning of it	Notice; see below
Date you received the notice	Not the date printed on the letter	Envelope, portal timestamp
Your address, phone, email	Where the answer should go	—
Representative, if any	Name, relationship, and the signed authorization	The plan's authorization form

Two of those lines are enforceable rather than merely helpful. A non-grandfathered plan's notice has to carry information sufficient to identify the claim involved, including date of service, provider, and claim amount (45 CFR 147.136(b)(2)(ii)(E)(1)). And on request, the plan must give you the diagnosis code and the treatment code and the meaning of each, "as soon as practicable" — and it may not treat that request, by itself, as your appeal ((E)(2)). If your notice arrived without those codes, ask for them in a separate message alongside the appeal, and do not let the request eat into the filing window.

One quiet way appeals go wrong here: a single letter arguing about three different claim numbers can get logged against one of them, and the other two stay denied while you wait for an answer that will never mention them. If two dates of service were denied for the same reason and you want them handled together, say so in one sentence and list both numbers twice — once in the identifier block, once in the decision you ask for at the end.

Their reason, quoted, before any of yours

The next block is short and belongs to them. Reproduce the denial reason word for word, in quotation marks, with the code attached, and say where it appears. The example below is invented — the date, the policy number and the claim numbers used throughout this page are made up, and the only real thing in it is the code text:

The notice dated 12 August 2026 states: "Services denied. CO-50 — These are non-covered services because this is not deemed a 'medical necessity' by the payer," and refers to medical policy MP-000.

The words after the dash are not a description of you or of your record. CO is a group code, 50 is a claim adjustment reason code, and that wording is the definition X12 publishes for reason code 50 (last modified 1 July 2017, read 7 September 2026) rather than a sentence anybody wrote about your file. Copying it exactly is what lets you show later that you answered the ground actually given. Which strings on a notice are standard codes and which are the plan's own file references is sorted out in CARC and RARC codes on your EOB.

Quoting rather than paraphrasing does something specific: it pins the plan to one ground. An appeal that answers a paraphrase invites an answer that quietly changes the subject to a reason the first notice never gave. A quoted ground has to be either upheld or abandoned.

It also exposes what is missing. The reason given has to include the denial code and its meaning, and a description of the plan's standard, if any, that was used in denying the claim (45 CFR 147.136(b)(2)(ii)(E)(3)). If your notice names a policy number and nothing else, that absence is worth a sentence of its own, and it is the reason your letter will be asking for the document. What a compliant notice has to carry, item by item, is set out in how to read a denial letter.

One sentence that says what you are disputing

This is the sentence a reviewer reads to learn what they are being asked to check, and it is the one most often missing. It is not "I believe this decision is unfair." It is a claim about where the decision went wrong. Four families cover most appeals, and they produce different letters:

What you are disputing	The sentence sounds like	What the letter mostly consists of
The criteria were applied to an incomplete record	"The plan applied MP-000 to a file that did not contain the 14 March operative note."	Records, dates, an exhibit list
The record meets the criteria and was read wrongly	"The record satisfies each of the four elements of MP-000, as set out below."	Element-by-element matching
The service is covered under the plan's own language	"Section 6.4 of the plan document covers this service, and the notice cites no exclusion."	Quoted plan language
It is an administrative or coding problem	"The claim was processed as out-of-network for a provider listed in the plan's directory on the date of service."	Screenshots, directory printouts, a reprocessing request

The fourth is worth checking before writing anything long, because plans usually resolve coding and network errors through a reprocessing request rather than an appeal, and that route tends to be faster. A denial that is really a data error does not need an argument. It needs the right department and a corrected claim.

Answering with the plan's own basis

The body of the letter is where their standard meets your record, and its shape is dictated by the shape of theirs. A medical policy is almost always a numbered list of conditions. So the body becomes a numbered list of the same length, in the same order, using their numbering.

Each item does three things and then stops: restate the element in their words, state the fact that meets it, and point at the exhibit and page where that fact lives. "Element 2 requires six weeks of documented conservative therapy. Physical therapy ran from 3 February to 24 March 2026, seven weeks, across eleven visits. Exhibit C, pages 1 to 4."

Getting the criteria document is a separate errand and it comes first. Where the policy libraries are and how to read their version dates is covered in finding the medical necessity criteria, and the federal rule that makes the plan hand over what it relied on is in how to request your claim file. If the dispute is about plan language rather than clinical criteria, the question becomes which document governs, and the answer is not always the one handed out at open enrollment; that stack is sorted in SPD, EOC, or SBC.

One line to include here has nothing to do with your argument. If the plan generates or relies on new evidence during the appeal, or lands on a new rationale, it must give you that material free of charge and early enough that you can respond before the final internal determination issues (45 CFR 147.136(b)(2)(ii)(C)(1) and (2)). Asking for that in advance, in writing, costs you a sentence and makes a late surprise harder to justify.

The enclosure list, and the pages that stay home

Number the enclosures, label them by letter, and say how many pages each one runs. Then reference them by letter in the body. An appeal in which every assertion points to an exhibit and every exhibit answers a criterion is a document a reviewer can work through without hunting for anything.

The failure mode runs the other way. Two hundred pages of chart, unsorted, stapled behind a two-page letter. Somebody summarises that stack, and the two pages that decide the claim — the operative note and the therapy discharge summary — do not make the summary. Volume reads as thoroughness and functions as noise.

What generally earns its place:

The denial notice itself, and the EOB
The provider's letter, with dates, findings, and treatment history stated against the plan's criteria rather than as a general opinion
Specific chart pages, tabbed, each tied to a numbered element
Proof of things the plan may not have in front of it: a prior authorization approval, a network directory printout with its retrieval date, an earlier claim paid for the same service

What usually should not go in: your original records. HealthCare.gov's internal appeals page puts it plainly — keep your original documents and submit copies — with one carve-out worth noticing. The request for an internal appeal itself, and any form authorising somebody else to appeal for you, are the two things it says to send in the original, so make your own copies of those before they go. Leave out unrelated claims, other family members' records, correspondence about billing disputes with the provider, and the paragraph about how this has been the worst year of your life. That paragraph is true and it is not evidence, and it spends the reviewer's attention in the part of the page where attention is worth the most.

Several state insurance departments publish model letters organised roughly this way. Washington's insurance commissioner posts examples for common denial reasons, which are among the easier ones to adapt. Outside Washington, the National Association of Insurance Commissioners covers the same ground, sample letter included, in its consumer guide How to Appeal Denied Claims (PDF). Adapt the skeleton, not the sentences. A letter that still reads like a template tells the reviewer nothing about your claim.

Ask for a decision, in the words of a decision

Close by naming the outcome you want in the terms the plan uses internally, so that granting it is a single action rather than an act of interpretation.

I request that the plan reverse the adverse benefit determination on claim 2026-0847391 and process the 14 March 2026 date of service at the in-network benefit level under section 6.4 of the plan document.

Then five procedural requests, each with a rule behind it and each useful whether you win or lose:

Copies of all documents, records, and other information relevant to the claim, free of charge (29 CFR 2560.503-1(h)(2)(iii)).
Identification of any medical or vocational experts whose advice the plan obtained, whether or not it relied on that advice ((h)(3)(iv)). The specialty of the professional consulted on review is worth asking for in the same sentence: the rule requires that person to have training and experience in the field of medicine involved ((h)(3)(iii)), which is checkable only if you know the field.
A copy of any internal rule, guideline, protocol, or similar criterion relied on, free of charge ((j)(5)(i)). Asking for the version number and effective date alongside it is a practical addition rather than something the paragraph requires, and it is what tells you whether the edition applied was the one in force on your date of service.
Where the denial rests on medical necessity, or on an experimental-treatment or similar exclusion, an explanation of the scientific or clinical judgment behind it, applying the terms of the plan to your medical circumstances ((j)(5)(ii)).
If the determination is upheld, a written final internal adverse benefit determination carrying the description of the available internal appeals and external review processes, and of how to initiate an appeal, that the notice rules require (45 CFR 147.136(b)(2)(ii)(E)(4)).

The last of the five is the one most often skipped, and it is the one that keeps the next track open.

Two clocks belong in the letter, and one belongs on the wall

Write the filing date into the letter. Then write the plan's answer date on a calendar before you seal the envelope.

Clock	Length	Source
File an internal appeal, group health plan	At least 180 days from receipt of the adverse determination	29 CFR 2560.503-1(h)(3)(i)
File an internal appeal, ERISA disability plan	At least 180 days — (h)(4) applies (h)(3)(i) to these claims	(h)(4) with (h)(3)(i)
File an internal appeal, other ERISA benefit claims	At least 60 days	(h)(2)(i)
Plan's decision, claim involving urgent care	72 hours	(i)(2)(i)
Plan's decision, pre-service claim	30 days; 15 days per level where the plan has two	(i)(2)(ii)
Plan's decision, post-service claim	60 days; 30 days per level where the plan has two	(i)(2)(iii)(A)
Request external review	Within four months of receipt of the notice	45 CFR 147.136(d)(2)(i); a state process must allow at least four months, (c)(2)(vi)

HealthCare.gov states the 180-day figure in the same plain terms and adds that in an urgent situation you can ask for external review at the same time as the internal appeal. Note what the regulation actually says, though: these are floors rather than fixed periods. A plan is free to allow more than 180 days. It is not free to allow less.

Check the table against your own coverage before you trust a date in it, because the 29 CFR numbers are ERISA's and not everybody is under ERISA. Individual-market coverage reaches the same standards by a different route: 45 CFR 147.136(b)(3)(i) makes an individual-market issuer follow 29 CFR 2560.503-1 as if it were a group health plan, leaving out the multiemployer provisions. Those provisions are the next wrinkle. Where a multiemployer plan's named fiduciary is a board or committee of trustees that meets at least quarterly, a post-service appeal is decided by the date of the next such meeting rather than in 60 days ((i)(2)(iii)(B)), and a request filed within 30 days of a meeting can roll to the one after it.

Two kinds of coverage are outside the table altogether. Grandfathered plans sit largely outside 45 CFR 147.136, which says so at (a)(1)(ii) — though the external review paragraphs (c) and (d) do reach them for out-of-network emergency care, nonparticipating providers at participating facilities, and air ambulance claims. And Medicare, Medicare Advantage, and Medicaid run on their own timetables entirely, with their own notices and their own levels; the Medicare ladder is laid out in the five levels of a Medicare appeal. A letter written against the numbers above is aimed at the wrong rulebook if that is your coverage.

Whether a state insurance department can do anything for you at all turns on one further fact about your plan, which is why self-funded or fully insured is worth settling before you need it. Which track the letter is on, and when the four-month clock actually starts running, is mapped in internal appeal vs external review.

Sending it so that the date can be proved

The date you filed is a fact you may need to establish months later, possibly to somebody who is not the insurer. Pick a route that generates evidence.

Plan portal. Fastest, and it timestamps. Screenshot the confirmation, save the reference number, and download whatever receipt it offers before closing the tab.
Fax. Still the default at many plans. Keep the transmission report; it carries the number, the page count, and the time.
Certified mail, return receipt requested. Slower, and the only route that produces a signature. Worth it when a deadline is close or the amount is large.
Email. Only if the plan named an address for appeals in writing. Ask for a delivery receipt and keep the sent copy.

For a claim involving urgent care, the request for an expedited appeal may be submitted orally, and information has to travel between you and the plan by telephone, fax, or another similarly expeditious method (29 CFR 2560.503-1(h)(3)(vi)). Make the call, then send the same thing in writing the same day, so the record holds a document rather than a memory.

Keep a call log with the date, time, name, and title of whoever you spoke to, and what they said. Log the enclosure list as well, because if the plan later says something was never submitted, the difference between a numbered list with page counts and a general recollection is the entire argument.

The last read-through, with a pen

Print it and read it the way the reviewer will, from the top, with no knowledge of you.

Can they tell in the first ten seconds which claim this is about, and which appeal level it is? Is the denial reason quoted rather than described? Is there one sentence saying what is being disputed? Does every element of their standard get an answer, and does every answer name an exhibit by letter and page? Is there a sentence asking for a specific decision, and another asking for the final determination in writing if the answer is no? Is the filing date on the letter, and the answer date on your calendar?

Then make the copy before it goes, not after.

This page describes documents and procedure. It is not legal or medical advice, and no licence sits behind it — which is why every deadline above carries a paragraph number instead of an assurance. Use the numbers. Open a section link before you rely on a date, and look at the date the eCFR says that text is current to, because it moves and this page will not move with it. For anything that turns on your own condition or your own contract, the notice you were sent has to carry contact details for your state's office of health insurance consumer assistance or ombudsman (45 CFR 147.136(b)(2)(ii)(E)(5)) — free help, and closer to your file than any page on the internet. Found something here that no longer matches the regulation? The contact page reaches me, and the about page sets out who is writing and on what basis.