What is a medical necessity denial?

A medical necessity denial means your insurance company claims the treatment your doctor ordered did not meet its clinical criteria. This does not mean your doctor was wrong — it means the insurer disagreed. You have the legal right to appeal.

Can I appeal a medical necessity denial?

Yes. You have a legal right to appeal any health insurance denial. Studies show over 40% of appeals are overturned when properly submitted. Most plans give only 30 to 180 days to file — act quickly.

How long do I have to appeal a health insurance denial?

Appeal deadlines are typically 30, 60, or 180 days from the denial letter date. Missing this deadline permanently forfeits your right to appeal. Check your denial letter or call your insurer immediately.

Is this template attorney-drafted?

Yes. This appeal letter template was drafted by an attorney with over a decade of insurance law experience. It is editable, includes a video tutorial, and is available as an instant download.

Why was my claim denied for out-of-network care?

Insurance companies deny out-of-network claims when the provider is not in their approved network. Many of these denials are wrongful — especially when care was urgent, when no in-network provider was reasonably available, or when you had no choice of provider in an emergency.

Can I appeal an out-of-network insurance denial?

Yes. You have the right to appeal, particularly if care was medically urgent, no in-network alternative was available, or the insurer failed to properly apply the No Surprises Act or state network adequacy rules.

What is the No Surprises Act?

The No Surprises Act protects patients from surprise bills for emergency care and for non-emergency care at in-network facilities by out-of-network providers when you had no meaningful choice of provider.

My insurance says my treatment is not covered — can I appeal?

Yes. Even when an insurer says a treatment is not covered or a policy exclusion applies, you can appeal. Many of these denials are based on ambiguous policy language or outright errors. An appeal forces the insurer to justify its reading of the policy.

What is a policy exclusion denial?

A policy exclusion denial means the insurer claims a specific clause in your policy excludes the treatment you received. These exclusions must be clearly stated — if the insurer cannot point to exact policy language, the denial may be wrongful and appealable.

Can I appeal a prior authorization denial?

Yes. You can appeal a prior authorization denial whether prospective, concurrent, or retrospective. Even if authorization was not obtained before care, you may have valid grounds — especially if care was urgent or the insurer's authorization process was unclear.

What if I had an emergency and could not get prior authorization?

Emergency care cannot legally require prior authorization. Cite the Emergency Medical Treatment and Labor Act (EMTALA) and your state emergency care laws in your appeal. Federal and state law require insurers to cover emergency stabilization regardless of prior authorization status.

How fast must insurers respond to a prior authorization appeal?

For urgent or ongoing care, you qualify for an expedited appeal — insurers must respond within 72 hours. For standard prior authorization appeals, deadlines are typically 30 days for pre-service decisions.

Can I appeal an experimental treatment denial?

Yes. Experimental or investigational treatment denials are among the most successfully appealed when the right evidence is presented. Insurers often apply outdated clinical criteria. A strong appeal presents published studies, clinical guidelines, and your physician's statement.

What evidence do I need to appeal an experimental treatment denial?

The strongest appeals include peer-reviewed clinical studies, published guidelines from major medical societies such as the AMA or ASCO, your treating physician's letter explaining why treatment is appropriate for your specific condition, and documentation showing the insurer's criteria are outdated.

What does denial code PR-1 mean?

PR-1 means Deductible Amount — Patient Responsibility. The insurer is applying the charge to your deductible. However, PR-1 denials are frequently incorrect — caused by calculation errors, timing issues, incorrect coordination of benefits, or provider and payer miscommunication.

Can I appeal a PR-1 deductible denial?

Yes. You can appeal if your deductible has already been met, if claims were processed in the wrong order, if there was a coordination-of-benefits error, or if the insurer incorrectly tracked your deductible accumulation.

What does denial code CO-167 mean?

CO-167 means the diagnosis code submitted does not justify the procedure billed. CO-167 denials are often caused by coding errors at the provider's billing office — not by a genuine lack of medical necessity.

How do I appeal a CO-167 diagnosis procedure mismatch denial?

Contact your provider's billing department to verify which codes were submitted. If codes were incorrect, ask the provider to resubmit. If codes were correct, file an appeal demonstrating the diagnosis supports the procedure using medical records and physician documentation.

What should I do first when my health insurance claim is denied?

Read the denial letter to find the denial reason and appeal deadline. Call your insurer for clarification. Gather your medical records, EOB, and insurance policy. File a formal internal appeal before the deadline — typically 30 to 180 days. Missing the deadline permanently forfeits your appeal rights.

Do I need a lawyer to appeal a health insurance denial?

No. Most health insurance denials can be appealed successfully without a lawyer using a well-structured appeal letter, your medical records, and your doctor's support. Attorney-drafted templates give you professional legal framing without the cost of retaining a lawyer.

What are the most important tips for winning a health insurance appeal?

Always file before the deadline. Address the specific denial reason rather than writing a generic letter. Get a detailed medical necessity letter from your treating physician. Include all relevant medical records. Cite clinical guidelines supporting your treatment. Send via certified mail and keep copies of everything.

What is the biggest mistake people make when appealing an insurance denial?

Writing a generic appeal that does not directly address the insurer's stated reason for denial. Each denial type requires different legal and clinical arguments. Match your arguments to the denial code and reasoning in your denial letter.

Are insurance companies using AI to deny claims?

Yes. Many major health insurers now use automated AI systems to review and deny claims — often without meaningful human review. These automated denials are legally challengeable through the standard appeal process.

What are the most common reasons health insurance claims are denied?

The most common reasons are: lack of prior authorization, treatment deemed not medically necessary, out-of-network provider, policy exclusion, diagnosis and procedure code mismatch (CO-167), deductible not met (PR-1), and experimental or investigational treatment classification. Most are appealable.

What is the difference between an internal and external insurance appeal?

An internal appeal is reviewed by your insurance company and is the required first step. An external appeal is reviewed by an independent organization — and its decision is legally binding on the insurer. Under the ACA, most health plans must offer external review after an internal appeal denial.

Mental Health Claim Denied? Your Insurer May Be Breaking the Law.

Jun 2

Written By Tatiana Kadetskaya

Mental health denials are not just frustrating. Many of them are illegal.

If your health insurance denied coverage for therapy, psychiatric care, substance use treatment, or inpatient mental health services, you are dealing with one of the most common — and most legally vulnerable — types of insurance denials in the country.

Here is what most patients don't know: federal law requires your health insurance plan to cover mental health and substance use disorder treatment on the same terms as physical health treatment. When insurers apply stricter criteria to mental health claims than they would for a comparable medical or surgical claim, they are violating the Mental Health Parity and Addiction Equity Act — a federal law with real enforcement teeth.

This changes how you appeal. And it gives you arguments most patients never use.

What is the Mental Health Parity and Addiction Equity Act?

The Mental Health Parity and Addiction Equity Act — commonly called the federal parity law — was enacted in 2008 and significantly strengthened by the Consolidated Appropriations Act of 2021. It applies to most employer-sponsored health plans and insurance plans sold on the ACA marketplace.

The law requires that any limits your plan places on mental health or substance use disorder benefits — visit limits, prior authorization requirements, step therapy protocols, day limits for inpatient stays — cannot be more restrictive than the limits applied to analogous medical and surgical benefits.

In plain terms: if your plan doesn't require prior authorization before you see a cardiologist, it generally cannot require prior authorization before you see a psychiatrist. If your plan doesn't limit how many times you can see your primary care physician in a year, it generally cannot limit your therapy visits.

The 2021 updates went further, requiring insurers to perform and disclose comparative analyses showing that they are actually complying with parity — and giving regulators and patients the right to demand those analyses.

The most common mental health denial types — and the parity argument for each

1. Therapy visits denied or limited

Many plans impose annual visit limits on therapy or behavioral health services — 20 sessions per year, for example — that do not apply to equivalent physical health services. This is a classic parity violation.

If your insurer has denied a therapy claim because you exceeded your annual visit limit, your appeal can argue that the same limit does not apply to comparable medical services and that the restriction therefore violates federal parity law. Cite the Mental Health Parity and Addiction Equity Act by name and request the plan's comparative analysis demonstrating parity compliance.

2. Inpatient psychiatric stay denied as "not medically necessary"

Inpatient psychiatric admissions are among the most aggressively denied mental health claims. Insurers routinely discharge patients — or refuse to authorize continued stays — by applying internal medical necessity criteria that are far more restrictive than those used for medical or surgical inpatient care.

Your appeal needs to address two arguments simultaneously: first, the standard medical necessity argument showing why continued inpatient treatment was clinically required; second, the parity argument showing that the insurer's criteria for authorizing continued psychiatric care are more restrictive than the criteria applied to comparable medical admissions.

The letter of medical necessity from your treating psychiatrist is essential here. It must document the specific clinical reasons why inpatient treatment was required and why outpatient alternatives were not safe or appropriate at the time.

3. Residential or intensive outpatient treatment denied

Residential treatment programs and intensive outpatient programs (IOPs) for mental health and substance use disorders are frequently denied on the grounds that "less intensive" care is available. Insurers apply step-down criteria to mental health treatment that they would not apply to physical rehabilitation or post-surgical care.

This is a parity argument. If your insurer would authorize a skilled nursing facility or inpatient rehabilitation for a comparable physical condition, it generally cannot deny residential mental health treatment on the basis that outpatient therapy is sufficient.

4. Prior authorization denied for therapy or psychiatric medication

Prior authorization requirements for mental health services — therapy, psychiatric medication, substance use treatment — that are not applied to comparable physical health services are a parity violation. Your appeal should identify the specific prior authorization requirement and ask the insurer to demonstrate that an equivalent requirement exists for analogous medical or surgical services.

5. Therapy denied as "not medically necessary"

Insurers sometimes deny ongoing therapy claims by arguing the treatment is no longer medically necessary — that you are maintaining stability rather than actively improving. This standard is applied far more aggressively to mental health treatment than to physical health treatment, where maintenance therapy and chronic condition management are routinely covered.

Your appeal here combines a medical necessity argument — your treating therapist or psychiatrist documenting why continued treatment is clinically required — with a parity argument showing the insurer would not apply the same "maintenance" standard to a comparable physical health condition.

How to structure a mental health parity appeal

A mental health appeal that invokes parity law has a different structure than a standard medical necessity appeal. It needs to do two things at once.

Part 1 — The medical necessity argument

This is the same foundation as any other medical necessity appeal. You need:

A letter from your treating mental health provider — therapist, psychiatrist, or treatment program clinical director — documenting why the treatment is medically necessary, what would happen without it, and why less intensive alternatives are not appropriate
Your diagnosis with DSM-5 diagnostic codes
Treatment history showing the progression of your condition and prior treatments
Clinical guidelines from organizations like the American Psychiatric Association or SAMHSA that support your treatment

Part 2 — The parity argument

This is what makes a mental health appeal different. You need to:

Identify the specific restriction your insurer applied — visit limit, prior authorization requirement, medical necessity criteria, day limit, step therapy requirement
Request in writing the insurer's comparative analysis showing that the same restriction applies to analogous medical and surgical benefits under your plan
Cite the Mental Health Parity and Addiction Equity Act (29 U.S.C. § 1185a for ERISA plans; 42 U.S.C. § 300gg-26 for ACA plans) and the 2021 Consolidated Appropriations Act amendments
Argue that the restriction violates federal parity law if no comparable restriction exists for physical health services

Most insurers do not want to produce a comparative analysis because many of them cannot demonstrate compliance. Requesting it formally shifts the dynamic of the appeal significantly.

What your treating provider's letter must address

Mental health appeals live and die on the quality of the clinical documentation. A proper letter of medical necessity from your mental health provider must:

State your diagnosis using DSM-5 criteria and codes
Document the severity and functional impact of your condition — not just the diagnosis, but how it affects your daily functioning, relationships, work, and safety
Explain why the specific level of care (outpatient therapy, IOP, residential, inpatient) is clinically appropriate and why a lower level of care is not safe or sufficient
Address the LOCUS criteria (Level of Care Utilization System) or ASAM criteria (American Society of Addiction Medicine) if the insurer referenced those standards in the denial
Document any prior treatment, prior hospitalizations, or prior failed attempts at lower levels of care
State explicitly what the clinical risk is if the treatment is discontinued or reduced

A note that says "patient is benefiting from therapy and should continue" will not win a mental health appeal. A letter that documents functional impairment, clinical risk, failed alternatives, and the specific reasons why this level of care is required has a real chance.

Which template do I need for a mental health appeal?

The right template depends on the specific denial reason:

"Not medically necessary" (therapy, inpatient, IOP, residential) → Medical Necessity Appeal Letter — $29
"Not covered" / policy exclusion (plan claims mental health treatment is excluded) → Policy Exclusion Appeal Letter — $29

Both templates are written by a licensed insurance attorney. Both include structured sections where you incorporate your parity law arguments alongside the standard medical necessity or exclusion challenge.

Not sure which applies to your denial? Answer 3 questions and find out →

Your right to external review

If your internal appeal is denied, you have the right to external review by an Independent Review Organization. For mental health parity violations specifically, you can also file a complaint with:

Your state's Department of Insurance
The U.S. Department of Labor (for ERISA employer plans)
The U.S. Department of Health and Human Services (for ACA marketplace plans)

Regulators take parity violations seriously. Filing a complaint in parallel with your appeal is not just allowed — it often accelerates the insurer's response.

Check your appeal deadline before you do anything else. Mental health appeal deadlines follow the same timelines as other health insurance appeals — typically 30 to 180 days from the denial date. Check your insurer's deadline →

Appeal Denied Mental Health Claim

Mental health insurance denials are common. Many of them are wrong. And a significant number of them are illegal under federal parity law.

Filing a properly structured appeal — one that combines a strong medical necessity argument with an explicit parity law challenge — gives you real leverage that most patients never use. Your insurer knows this law exists. When you cite it correctly, you change the conversation.

Get the Medical Necessity Appeal Letter Template — $29 →

Get the Policy Exclusion Appeal Letter Template — $29 →

Frequently Asked Questions

Does the mental health parity law apply to my plan?

The Mental Health Parity and Addiction Equity Act applies to most employer-sponsored group health plans with more than 50 employees and to individual and small group plans sold on the ACA marketplace. It does not apply to retiree-only plans, plans with fewer than 2 participants, or certain grandfathered individual plans. If you are unsure, check your Summary Plan Description or contact your plan administrator.

My insurer says my therapy is no longer medically necessary because I'm "stable." Can I appeal?

Yes — and this is one of the strongest parity arguments available. Insurers routinely cover ongoing medical treatment for stable chronic physical conditions (diabetes management, cardiac monitoring, ongoing physical therapy) while cutting off mental health treatment for patients who have achieved stability. That inconsistency is a parity violation. Document it in your appeal.

Can I appeal a mental health denial that happened more than a year ago?

It depends on your plan. Most plans require internal appeals to be filed within 30 to 180 days of the denial notice. If that deadline has passed, the internal appeal route may be closed — but you may still be able to file a complaint with your state insurance commissioner or the U.S. Department of Labor for parity violations, which have separate timelines.

What is the LOCUS or ASAM criteria and why does my insurer keep citing it?

LOCUS (Level of Care Utilization System) and ASAM (American Society of Addiction Medicine Patient Placement Criteria) are clinical frameworks used to determine the appropriate level of mental health and substance use treatment. Insurers sometimes use these criteria to justify denying higher levels of care. Your appeal should engage with these criteria directly — your provider's letter should address them and explain why, under those same criteria, your level of care is clinically appropriate.

What is a comparative analysis and how do I request one?

A comparative analysis is a document insurers are required to produce under the 2021 parity amendments showing that they apply mental health and substance use disorder benefit restrictions no more stringently than comparable medical and surgical restrictions. You can request it in writing from your insurer or plan administrator. If they cannot or will not produce it, that itself is evidence of a potential parity violation to include in a regulatory complaint.

Tatiana Kadetskaya