The denial letter arrives in the mail. Your child's speech therapy, occupational therapy, or ABA services won't be covered. The reason: "not medically necessary." You've been through months of evaluations, your pediatrician wrote the referral, and your child's therapist documented progress in every session. The denial doesn't make sense, and you don't know what to do next.

There's a formal process. It has real deadlines, real legal protections, and real consequences if your insurer doesn't follow the rules. Most families don't know it exists. Here's how to navigate it.

What the Denial Letter Must Tell You

Federal law requires your insurer to send a written denial that includes specific information. If any of this is missing, you can challenge the denial on procedural grounds alone.

The letter must state:

• The specific reason for the denial
• The clinical criteria or medical policy the insurer used to make the decision
• Your right to appeal and the deadline to file
• Instructions for requesting the documents the insurer reviewed

If the denial says "not medically necessary" but doesn't cite the clinical criteria or policy used, that's a procedural violation you should document in your appeal letter.

Some denials cite policies you've never seen. Your insurer can't hold your child's care to a standard they didn't share with you upfront. Request a copy of the clinical guidelines or medical policy referenced in the denial letter. You're entitled to it.

The Internal Appeal Process: First and Second Level

You have 180 days from the date of the denial to file an internal appeal. This is the clock that matters. Don't wait for your therapist to call the insurance company or for your pediatrician to submit more notes. The 180-day window runs whether or not anyone makes a phone call.

What to Gather

Your appeal needs documentation that answers the insurer's reason for denial. Collect these before you file:

• Explanation of Benefits (EOB) showing what was denied and why
• The denial letter with the clinical criteria cited
• Letter of medical necessity from your child's treating provider or diagnosing physician. This should explicitly address why the therapy meets the insurer's stated criteria and cite progress data, diagnostic codes, and treatment goals.
• Treatment plan submitted with the original prior authorization request
• Progress notes from recent sessions showing measurable improvement or maintenance of function
• Peer-reviewed literature supporting the therapy for your child's diagnosis (if the denial called the treatment "experimental" or "not evidence-based")

If the denial was based on "not medically necessary," the medical necessity letter is your most important document. It should be written by the provider who evaluated your child, not the billing department. It needs to cite the same clinical standards the insurer used and explain how your child meets them.

Filing the First-Level Appeal

Most insurers require a written appeal submitted by mail or through their online portal. Phone calls don't count. Submit your appeal in writing and keep a copy of everything you send.

Include:

• A cover letter stating you're filing a first-level internal appeal under the ACA (Affordable Care Act) and MHPAEA (Mental Health Parity and Addiction Equity Act)
• The denial letter and EOB
• All supporting documentation listed above
• Your contact information and policy number

The insurer has 30 days to respond to a non-urgent appeal. If the denial affects care your child is currently receiving (called a concurrent care denial), the insurer must respond within 72 hours. If they don't meet the deadline, you can escalate to external review.

Second-Level Appeal

If the first-level appeal is denied, you can file a second-level appeal with the insurer. You have the same 180-day window from the original denial. The process is the same: written submission, supporting documentation, and a response deadline.

Some plans skip the second level and move directly to external review after the first denial. Check your plan documents or call member services to confirm how many internal appeal levels your plan requires.

External Review: State or Federal

Once you've exhausted internal appeals, you have the right to external review. This means an independent third party reviews the denial and makes a binding decision. The insurer must follow the external reviewer's determination.

Who handles your external review depends on whether your plan is fully insured or self-funded.

Fully Insured Plans (State External Review)

If your plan is fully insured (purchased through the health insurance marketplace, directly from an insurer, or provided by a small employer), file your external review request with your state's Office of Patient Protection or equivalent agency.

You must file within four months of the final internal appeal denial. The state will assign an independent review organization (IRO) to evaluate whether the denial was appropriate based on medical evidence and the terms of your policy.

To find your state's external review process, search "[your state] health insurance external review" or call your state's insurance department.

Self-Funded Plans (Federal External Review)

If your plan is self-funded (common with large employers), it's governed by ERISA (Employee Retirement Income Security Act). Your external review request goes to the U.S. Department of Labor.

File online at dol.gov/agencies/ebsa or call 866-444-3272. You have four months from the final internal appeal denial to file.

The federal process works the same as the state process: an independent reviewer evaluates the denial and issues a binding decision.

How to tell if your plan is self-funded: Check your insurance card or member documents. If it says "administered by" an insurer but the plan name references your employer (e.g., "XYZ Company Health Plan"), it's likely self-funded. Call member services and ask directly: "Is this plan fully insured or self-funded under ERISA?"

Using the Mental Health Parity and Addiction Equity Act

MHPAEA requires insurers to treat autism therapies and other behavioral health benefits the same way they treat medical and surgical benefits. If your insurer applies stricter rules to ABA, speech, or OT than they do to physical therapy or diabetes care, that's a parity violation.

Common violations include:

• Requiring more documentation for autism therapy prior authorization than for comparable medical treatments
• Imposing visit limits on ABA or speech therapy that don't exist for physical therapy
• Using different clinical criteria for behavioral health services than for medical services
• Denying therapy as "not medically necessary" based on standards they don't apply to medical care

If you suspect a parity violation, state it explicitly in your appeal. Write: "This denial appears to violate the Mental Health Parity and Addiction Equity Act. I'm requesting documentation showing that the clinical criteria and authorization requirements applied to this therapy are no more restrictive than those applied to medical and surgical benefits under this plan."

The insurer must respond. If they can't demonstrate parity, the denial should be overturned.

You can also file a parity complaint with your state insurance department or the U.S. Department of Labor, even while your appeal is pending.

What Happens During the Appeal

Federal law requires insurers to continue authorizing previously approved services at the prior level while your appeal is pending. This applies when the denial is a reduction or termination of ongoing care, not when the request is for new services.

If your child was receiving 10 hours of ABA per week and the insurer reduced it to 5, they must continue the 10 hours during the appeal. You don't have to accept the reduced level while fighting the decision.

To invoke this right, call member services immediately after filing your appeal and state: "I'm requesting continuation of benefits during the appeal period under ACA Section 2719." Document the call: date, time, representative name, and what was said.

If All Appeals Fail

External review is binding, but it's not the end of your options. If the external reviewer upholds the denial, you can:

File a Complaint with Your State Insurance Commissioner

State insurance departments investigate whether insurers are following state mandates and federal law. All 50 states have autism insurance mandates requiring coverage of ABA, speech, and OT. If your insurer is denying care required under state law, the insurance commissioner can intervene.

Find your state's complaint process at your state insurance department's website or by calling their consumer assistance line.

Contact Your State Attorney General's Office

If the denial appears to violate state law (such as refusing to cover therapy mandated under your state's autism insurance law), file a complaint with the AG's consumer protection division. Some states actively enforce insurance mandates through AG investigations.

Consult a Private Attorney

Attorneys who specialize in insurance bad faith or ERISA claims can evaluate whether your insurer violated your plan or federal law. Many work on contingency (no upfront fees) if they believe the case has merit.

Bar associations in most states have referral services for health law and insurance attorneys.

Apply for Medicaid (If Income-Eligible)

If your family qualifies based on income, Medicaid covers ABA, speech, and OT for children with disabilities in all states. Coverage is generally more comprehensive than private insurance and doesn't require prior authorization in the same way.

If your child is eligible for a Medicaid waiver, be aware that waiting lists can be years long in some states. Check your state's Medicaid eligibility at your state's health department website or healthcare.gov.

Access Services Through Your School District

Children ages 3 to 21 are entitled to special education services under IDEA (Individuals with Disabilities Education Act) if their disability affects their education. This includes speech therapy, occupational therapy, and related services.

If your child doesn't already have an IEP (Individualized Education Program), request an evaluation in writing from your school district. The district must evaluate within 60 days and provide services at no cost if your child qualifies.

School-based services aren't a substitute for medical therapy, but they can fill gaps while you pursue other coverage options.

Common Denial Reasons and How to Counter Them

"Not Medically Necessary"

This is the most common denial reason. It means the insurer believes the therapy doesn't meet their clinical criteria for coverage.

How to counter it: Get a detailed medical necessity letter from your child's provider that cites the insurer's clinical criteria and explains how your child meets each element. Include progress data, diagnostic codes, and treatment goals. If the insurer didn't share their clinical criteria upfront, demand a copy and note the procedural violation in your appeal.

"Experimental or Investigational"

Insurers sometimes deny ABA or other autism therapies by calling them experimental, even though decades of peer-reviewed research support them.

How to counter it: Submit peer-reviewed studies from reputable journals showing the therapy is evidence-based and widely accepted as standard care. Include clinical practice guidelines from organizations like the American Academy of Pediatrics or the American Speech-Language-Hearing Association. Cite your state's autism insurance mandate, which typically defines these therapies as medically necessary.

"Educational, Not Medical"

Some insurers deny therapy by claiming it's educational rather than medical, and therefore the school district's responsibility.

How to counter it: Therapy that addresses medical needs (improving speech production, sensory integration, functional communication) is medical care, even if it also helps your child in school. The provider's letter should distinguish between medical goals and educational goals. Note that the school's obligation under IDEA doesn't eliminate the insurer's obligation under your policy.

"Provider Not Licensed or Not in Network"

Denials based on provider qualifications or network status are straightforward to address if the facts are on your side.

How to counter it: Submit proof of the provider's credentials (license number, certifications). If the provider is out of network but there are no in-network providers within a reasonable distance, request a single-case agreement that allows your child to see the out-of-network provider at in-network rates. Many states require insurers to grant these when network adequacy is insufficient.

Timelines and Deadlines to Know

• 180 days to file internal appeal from the date of the original denial
• 30 days for the insurer to respond to a non-urgent internal appeal
• 72 hours for the insurer to respond to an urgent or concurrent care appeal
• 4 months to file external review from the date of the final internal appeal denial

Miss a deadline and you lose the right to that level of appeal. Set calendar reminders for every filing date and every response deadline. If the insurer misses a deadline, note it in your next submission and escalate.

What You Need to Know About Prior Authorization

Most private insurance plans require prior authorization for ABA, speech, and OT. This means the provider submits a treatment plan and the insurer approves a certain number of hours or visits before care begins.

ABA authorizations typically last six months. Speech and OT are usually approved by number of visits (e.g., 20 visits per calendar year). When the authorization period ends, the provider must submit a new request.

Denials often happen at reauthorization, even when your child has been receiving the same therapy for months. The insurer may claim progress has plateaued or the therapy is no longer medically necessary. These denials are appealable using the same process.

Keep copies of all prior authorization approvals. If the insurer denies reauthorization for therapy they previously approved, note the inconsistency in your appeal. Ask why the clinical criteria changed or why progress documented in recent sessions doesn't support continuation.

Resources

• Autism Speaks Health Insurance Tool: Interactive guide for navigating insurance coverage and appeals
• Autism Insurance Resource Center (massairc.org): State-specific information on autism insurance mandates and appeal processes
• State Protection and Advocacy Organizations: Free legal assistance for families navigating insurance denials and special education disputes. Find your state's P&A at ndrn.org.
• ABLE Accounts: Tax-advantaged savings accounts that can help pay for therapy expenses while protecting eligibility for public benefits

The appeals process is bureaucratic and slow. It's designed to be. Insurers count on families giving up after the first denial. File the appeal anyway. Gather the documents. Invoke your rights under MHPAEA. Escalate to external review. The process exists because families before you fought for it, and it works when you use it.