Mental Health Insurance Claim Denied? How to Read the Letter and Appeal It

By the Editorial Team. Reviewed and updated on August 8, 2026.

This article is educational and independent. It is not medical, legal, or insurance advice, and it is not a diagnosis or a treatment recommendation. Coverage rules, benefit programs, and legal rights vary by state, by plan, and by individual circumstance. Confirm details with your plan, a licensed professional, or the official sources named in this article.

If you are in crisis or thinking about harming yourself, help is available right now, free and confidential. Call or text 988 to reach the 988 Suicide & Crisis Lifeline, or chat at 988lifeline.org. You can also text HOME to 741741 to reach the Crisis Text Line. For substance use or mental health treatment referrals, SAMHSA’s National Helpline is 1-800-662-4357. If someone is in immediate danger, call 911.

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Getting a mental health insurance claim denied usually arrives as a single page that manages to be both alarming and vague. It says the requested services do not meet criteria for medical necessity. It names criteria you have never seen. It gives you a deadline buried in the fourth paragraph, and it tells you that you may submit additional information without saying which information would actually change the answer.

Most people read it twice, feel sick, and put it in a drawer.

That is the worst possible move, and not for the reason you would expect. The problem is not that appeals are hopeless. Plans overturn a meaningful share of their own decisions at the internal appeal stage, particularly when new clinical documentation arrives with the appeal. The problem is that the clock starts on the date of the letter, and the drawer does not stop it.

A mental health insurance claim denied at the level-of-care stage is also one of the more appealable decisions in American health coverage, because it rests on clinical judgment that a second clinician can weigh differently.

This article covers what a denial letter is required to contain, why the type of plan you have changes your rights significantly, how internal appeals and external review actually work, and what kind of evidence tends to move a decision. Nobody can tell you your appeal will succeed. What can be said honestly is that a well-documented appeal is a different animal from a letter that says the treatment was necessary, and the difference is mostly work you can do yourself.

What “Mental Health Insurance Claim Denied” Actually Means on Paper

The legal term is adverse benefit determination. It covers any denial, reduction, or termination of a benefit, and it includes a rescission of coverage. Use that phrase in your correspondence. It tells whoever reads your appeal that you are working from the same rulebook they are.

Under federal claims regulations, an adverse benefit determination notice has to give you certain things. Not as a courtesy. As a requirement.

• The specific reason or reasons for the denial, in language you can understand.
• Reference to the specific plan provisions on which the determination is based.
• A description of any additional material or information needed to perfect the claim, and why it is needed.
• A description of the plan’s appeal procedures and the applicable time limits.
• If the decision relied on an internal rule, guideline, protocol, or clinical criterion, either a copy of it or a statement that a copy is available free of charge on request.
• If the denial is based on medical necessity or experimental treatment, an explanation of the scientific or clinical judgment applied to your circumstances, free of charge on request.
• For group health plans, a statement of your right to bring a civil action after exhausting the appeal process.

Read that list again, because the fifth and sixth items are the ones almost nobody exercises. You can ask for the criteria. You can ask for the reasoning. In writing, and at no cost.

The U.S. Department of Labor explains these obligations for employer-sponsored plans in its consumer guide, Filing a Claim for Your Health Benefits.

Three documents people confuse

Document	What it is	Does it start an appeal clock?
Explanation of Benefits (EOB)	A statement of how a claim was processed. Not a bill. Often the first place a denial appears, shown as a reason code.	Sometimes. If it communicates a denial, it can function as the notice. Check the date.
Adverse benefit determination letter	The formal denial notice with reasons, criteria references, and appeal instructions.	Yes. This is the document your deadline runs from.
Provider bill or statement	What the clinic or facility says you owe. Generated by the provider, not the plan.	No. But it is how most people find out something went wrong.

The Denial Reasons You Will Actually See

Nearly every mental health insurance claim denied in the United States falls into a small number of categories. Identifying which one you are facing determines everything you do next, because the evidence that fixes one does nothing for another.

Stated reason	What it usually means	What tends to address it
Not medically necessary	The documentation did not match the plan’s written criteria for that level of care	The plan’s actual criteria, plus a clinician letter answering each criterion with dated chart evidence
Level of care not appropriate / can be treated at a lower level	The plan agrees treatment is needed, but not at that intensity	Functional evidence and a documented history of what failed at the lower level
No prior authorization obtained	An administrative miss, sometimes by the facility rather than the patient	Proof of the request, a retro-authorization request, or an urgent-admission exception
Out-of-network provider	The clinician or facility has no contract with the plan	Out-of-network benefits, a network adequacy exception, or a documented lack of available in-network providers
Missing or insufficient documentation	Records were not submitted, arrived late, or were illegible	Complete records with dates, plus confirmation of receipt
Not a covered benefit / plan exclusion	The plan document genuinely excludes the service	Verify the exclusion language. If it applies only to behavioral health, that raises a parity question
Coding or billing error	Wrong procedure code, wrong place of service, wrong provider identifier	A corrected claim from the provider. Not an appeal at all

That last row saves people weeks. A surprising share of denials are billing mechanics, not coverage decisions, and the fix is a phone call to the provider’s billing office asking them to resubmit with corrected information. Check that before you write anything.

The parity angle worth checking

If the restriction that caused your denial applies more strictly to behavioral health than to comparable medical or surgical care, that may violate the Mental Health Parity and Addiction Equity Act (MHPAEA). Examples of the pattern: prior authorization required for every behavioral health admission but not for comparable medical admissions, or concurrent review conducted every three days for psychiatric care and every seven for medical care. Plans subject to the law must be able to produce a comparative analysis of any nonquantitative treatment limitation on request. Asking for it in an appeal changes the conversation, because it is a compliance question rather than a clinical one.

ERISA or Not: The Question That Changes Your Rights

Before you write a word, find out what kind of plan you have. This single fact determines your deadlines, who reviews your appeal, whether a state regulator can help you, and what happens if you eventually go to court.

	ERISA plan (most private employer coverage)	Non-ERISA (marketplace, individual, Medicaid, Medicare, government and most church plans)
Primary regulator	U.S. Department of Labor	State insurance department, state Medicaid agency, or CMS depending on program
Internal appeal	Generally one or two mandatory levels, per plan document	Usually one level, then state external review
External review	Federal external review process or a state process that meets federal standards	State external review program, or the federal process for plans without one
State insurance complaint	Generally unavailable for self-funded plans	Available and often effective
If you sue	Federal court under ERISA. In most cases the judge reviews the administrative record you built during the appeal, and no new evidence is added	State law claims may be available, with broader remedies in some states

Sit with that last row for a second, because it is the most consequential sentence in this article.

In an ERISA case, the record you create during the internal appeal is usually the entire record a court will ever see. Evidence you did not submit during the appeal generally cannot be added later. That is why experienced advocates treat the internal appeal as the main event rather than a formality. Everything goes in. The clinician letter, the full chart, the standardized measures, the call logs, the plan’s own criteria and your response to each element of them.

How do you find out which you have? Ask your employer’s HR or benefits contact whether the plan is self-funded or fully insured, or look at the Summary Plan Description. ERISA plans include a statement of ERISA rights, usually near the back. Government employee plans, church plans, individual market policies, Medicaid, and Medicare are not ERISA plans.

The Appeal Sequence, Step by Step

Here is the ordinary path, in order. Deadlines below are the federal minimum standards for non-grandfathered group health plans and marketplace coverage. Your plan document may be more generous. It cannot be less.

1. Day 0 — the denial letter is dated. Your clock starts here, not on the day you opened the envelope.
2. Within days 1-7 — request the file. In writing, ask for the plan’s written medical necessity criteria applied to your claim, the reviewer’s credentials and specialty, and a complete copy of the claim file including all documents the plan relied on. Federal rules entitle claimants under group health plans to these free of charge.
3. Days 7-30 — build the appeal. Get a clinician narrative that responds to the plan’s criteria element by element. Collect chart notes, discharge summaries, medication history, standardized scores over time, and anything documenting function.
4. Within 180 days — file the internal appeal. You generally have at least 180 days from the date of the adverse benefit determination to appeal a group health plan denial. Send it in a way that produces proof of delivery.
5. Plan decision. Pre-service appeals are generally decided within 30 days. Post-service appeals within 60 days. Urgent care appeals within 72 hours.
6. If upheld — request external review. You generally have 4 months from the final internal denial to request an independent external review. An independent review organization (IRO) assigns physicians with no financial relationship to the plan.
7. IRO decision. Standard external review decisions generally arrive within 45 days. Expedited external review is much faster, often 72 hours, and can run at the same time as an expedited internal appeal when care is urgent.
8. The IRO decision binds the plan. If the IRO overturns the denial, the plan must provide coverage. This is the part people do not realize, and it is the strongest reason not to stop after one internal appeal.

The Centers for Medicare & Medicaid Services explains the external review process and how to find your state’s program at CMS.gov’s appeals and external review page. HealthCare.gov also walks consumers through both stages at HealthCare.gov.

When care is happening right now

Ask for an expedited appeal if a delay would seriously jeopardize health or the ability to regain maximum function, or if the claim involves ongoing or urgent treatment. You can request it by phone, and the plan cannot require you to complete an internal appeal before an expedited external review in urgent situations. Two other things matter here. When a plan terminates coverage for care already in progress, that concurrent care decision generally requires advance notice and, in many cases, continued coverage while the appeal is pending. And your treating clinician can ask for a peer-to-peer review, a direct conversation with the plan’s physician reviewer, which sometimes resolves the matter before a formal appeal is decided.

What Actually Moves an Appeal

Sympathy does not move appeals. Specificity does. That is true whether the mental health insurance claim denied was for six therapy sessions or for a month of residential care.

The single most effective appeal document is a clinician letter written against the plan’s own criteria. Get the criteria first. Then have the treating clinician address each element in order, quoting dated chart evidence for each. A letter that says “the patient requires this level of care in my professional judgment” is easy for a reviewer to set aside. A letter that says “criterion 3.2 requires documented failure at a less intensive level within the prior 90 days; the patient completed 14 IOP sessions between March 3 and April 11 with worsening scores on a standardized measure administered on March 3, March 24, and April 10” is not.

Evidence that tends to carry weight:

• Functional detail. Not “severe symptoms” but what stopped working. Missed shifts with dates. Weight change. Inability to manage medication or meals. Loss of housing or transportation.
• Chronology. A dated timeline of treatment attempts, from first outpatient contact to the current request, showing the step-up logic.
• Standardized measures over time. Repeated scores from validated instruments give a reviewer something to compare against a criterion.
• Records from every treating clinician, not only the one requesting the service. Primary care notes, emergency department records, and pharmacy history all add texture.
• The plan’s own language. Quote the plan document provision the denial cited and explain, in one paragraph, why your facts satisfy it.

What tends not to help: emotional narrative without dates, letters from people who are not treating clinicians, printouts of general articles about the condition, and long complaints about the plan’s conduct. Save the conduct complaint for the regulator. Keep the appeal clinical.

Formatting that gets read

1. One page cover letter. Claim number, member ID, dates of service, the specific decision you want reversed, and a numbered list of what is enclosed.
2. The clinician letter next, addressing the criteria in order.
3. Records behind that, tabbed or bookmarked, in chronological order.
4. A short closing paragraph requesting the appeal decision in writing with the basis stated.

Send it with tracking. Keep a complete copy of everything you sent, exactly as sent.

A Worked Example (Illustrative Composite, Not a Real Person)

The following is a fictional composite created to show the sequence. It does not describe any real individual, plan, insurer, or facility.

Marcus is 41 and covered by his employer’s self-funded plan, which makes it an ERISA plan. After an emergency department visit in May, he is admitted to a residential program. The plan authorizes nine days. On day nine, concurrent review finds he no longer meets residential criteria and terminates coverage going forward. The program’s clinical team believes he needs three more weeks.

Day 9. The facility receives the verbal determination. Marcus’s spouse asks for the written adverse benefit determination the same day and asks, in writing, for the plan’s residential level-of-care criteria and the reviewer’s specialty.

Day 10. The treating psychiatrist requests a peer-to-peer review. The plan’s reviewer, a physician, upholds the decision. That is not the end of anything, but it is useful, because the psychiatrist now knows exactly which two criteria the reviewer considered unmet.

Day 11. Marcus requests an expedited internal appeal, since treatment is ongoing.

Days 11-13. The appeal package goes out: a two-page psychiatrist letter organized against the criteria, daily nursing notes from days 1-9, medication changes with dates, three administrations of a standardized measure, records of two prior outpatient episodes that ended in relapse, and a discharge plan naming a specific step-down intensity and the conditions for moving to it.

Day 14. The plan decides the expedited appeal. In this illustration it partially overturns, authorizing five more residential days followed by PHP. Not the three weeks requested.

Day 16. Marcus files for expedited external review on the remaining days. The IRO assigns a psychiatrist with no relationship to the plan.

Day 19. The IRO issues a decision. Whatever it says, it binds the plan.

Two things in this composite are worth pulling out. First, the peer-to-peer call that “failed” produced the most valuable information in the whole sequence, namely which criteria were at issue. Second, a partial overturn is a common and often overlooked outcome. Appeals are not always all-or-nothing.

Your Appeal Checklist

Print this or copy it into a document. Check items off with dates.

• [ ] Write the date of the denial letter at the top of your file. Calculate and note the 180-day deadline.
• [ ] Identify the exact denial reason and match it to the table above.
• [ ] Confirm with the provider’s billing office that this is not a coding or claim-submission error.
• [ ] Determine whether the plan is ERISA or non-ERISA.
• [ ] Request in writing: the medical necessity criteria applied, the reviewer’s credentials and specialty, and the complete claim file.
• [ ] Request the Summary Plan Description or Evidence of Coverage if you do not have it.
• [ ] Ask the treating clinician for a letter written against the criteria, element by element.
• [ ] Gather chart notes, discharge summaries, medication history, standardized measures, and dated functional evidence.
• [ ] Decide whether the appeal qualifies as urgent and request expedited handling if it does.
• [ ] Assemble the package with a numbered cover letter.
• [ ] Send with delivery tracking and keep a full copy.
• [ ] Calendar the plan’s decision deadline: 72 hours urgent, 30 days pre-service, 60 days post-service.
• [ ] If upheld, file for external review within 4 months of the final internal denial.
• [ ] Log every phone call: date, representative’s name, reference number, what was said.

One more habit worth building. After every call, send a short email or letter to the plan summarizing what you were told and asking them to correct you if it is wrong. That converts a phone conversation into a document.

Where to Get Free, Unbiased Help

None of these charge you, and none of them are selling a service.

• Employee Benefits Security Administration (EBSA), part of the U.S. Department of Labor. Benefits advisors answer questions about employer plan appeals and can sometimes contact a plan on a participant’s behalf.
• Your state Department of Insurance. For fully insured and individual market plans, the complaint process is free and often produces a written response from the insurer within weeks. Many states also run the external review program.
• State Consumer Assistance Programs, where they exist, help consumers file appeals directly.
• Protection and Advocacy agencies. Every state and territory has one, funded federally, working on rights issues for people with mental health conditions.
• Legal aid organizations and law school clinics, which sometimes take benefits cases at no cost based on income.
• SAMHSA’s National Helpline, 1-800-662-4357, for treatment referral and information, free and confidential, 24 hours a day.
• State Health Insurance Assistance Programs (SHIPs) for Medicare appeals counseling, free in every state.

Medicare and Medicaid denials follow their own appeal systems with their own deadlines and forms, which is why the generic advice above does not transfer cleanly. Medicare beneficiaries should start with the appeal instructions on the Medicare Summary Notice. Medicaid enrollees have a right to a state fair hearing, and in many states can request that benefits continue during the appeal if the request is filed quickly enough after the notice.

Frequently Asked Questions

My mental health insurance claim was denied. How long do I have to appeal?

For most group health plans and marketplace coverage, at least 180 days from the date of the adverse benefit determination for the internal appeal, then 4 months from the final internal denial to request external review. Your plan document may allow more time. Medicare and Medicaid run on different timelines stated in their own notices.

What is an adverse benefit determination?

The formal term for a denial, reduction, termination, or failure to pay a benefit, including a rescission of coverage. It is the trigger for your appeal rights.

Can I get the criteria the plan used to deny my care?

Yes. If a decision relied on an internal rule, guideline, protocol, or clinical criterion, group health plans must provide a copy free of charge on request, along with the scientific or clinical explanation applied to your circumstances for medical necessity denials.

Should my doctor appeal or should I?

Both roles matter and they are not interchangeable. The clinician supplies the clinical narrative and can request a peer-to-peer review. You control the appeal as the claimant, hold the deadline, and can authorize the provider to act on your behalf in writing if you prefer they file it.

Does an external review actually work?

Independent reviewers overturn plan decisions in a meaningful minority of cases, and behavioral health level-of-care disputes are among the categories that get overturned. No one can predict any individual outcome. What is certain is that the IRO’s decision binds the plan, so the process is not advisory.

Is an expedited appeal available for mental health care?

Yes, when a delay would seriously jeopardize health or the ability to regain maximum function, or when the claim involves urgent or ongoing care. Urgent internal appeals are generally decided within 72 hours, and expedited external review can run concurrently.

What if the denial says my provider is out of network?

Check three things. Whether your plan has out-of-network benefits at all, whether the provider was in network on the date of service, and whether you can document that no in-network provider was available within a reasonable distance and time. That third one supports a request for a network adequacy exception or single case agreement.

Can I complain to my state Department of Insurance?

If your plan is fully insured or purchased on the individual market, yes, and it is free. If your employer’s plan is self-funded, state regulators generally lack authority over it, and the Department of Labor is the right destination instead.

What if the plan misses its own decision deadline?

Under federal rules, a plan’s failure to follow claims procedures can allow a claimant to treat the internal process as exhausted and move directly to external review or, for group health plans, to court. Document the dates precisely if this happens.

Will appealing hurt my relationship with the plan or my employer?

Appealing is a benefit right, not a complaint against your employer, and your employer does not receive your clinical records. Plans process appeals as routine administrative work.

Do I need a lawyer to appeal?

Many appeals are filed by patients and families without one. What changes the calculus is an ERISA plan, a large dollar amount, or a case heading toward litigation, because the administrative record you build during the appeal is generally the record a federal court will review. This article does not give legal advice, and whether to seek counsel is an individual decision.

My mental health insurance claim was denied for a residential stay that already happened. Is it too late?

No. Post-service denials follow the same appeal path, with the plan generally required to decide within 60 days. Gather the full record from the facility, including daily notes, before you file.

Final Thoughts

Do one thing today. Find the denial letter, write the date it was issued at the top of a fresh page, and send a written request for the medical necessity criteria and the complete claim file. A mental health insurance claim denied for medical necessity can only really be answered with the plan’s own criteria in front of you. That request costs you nothing, it does not commit you to anything, and it turns an appeal you would be guessing at into one you can actually write.

Then take your time with the rest. You have months, not days, in most cases. Use them.

This article is for general informational purposes only and does not constitute medical, legal, insurance, or financial advice. It is not a diagnosis, a treatment recommendation, or an evaluation of any individual claim. Mental health coverage rules, parity requirements, appeal rights, disability standards, and employment protections vary by plan, by state, and by individual circumstance, and they change over time. This site is independently operated. It is not a law firm, an insurance company or advisor, a healthcare provider, a government agency, or an advocacy organization, and it does not represent anyone. Reading this article creates no professional relationship of any kind. Always confirm current requirements with your plan documents, a licensed professional in your state, or the official government sources cited above before making any decision.