When a health plan denies or cuts ABA therapy, most families focus on medical necessity: did the plan agree that the hours are needed? There is a second question worth asking: is the plan treating ABA the same way it treats comparable medical care? That is what federal mental health parity law is about. This guide explains parity in plain terms, what changed in 2025 and 2026, and how to use it when you challenge a denial. For the appeal steps themselves, see how to appeal an ABA denial in Florida.
What is mental health parity?
The Mental Health Parity and Addiction Equity Act (MHPAEA), at 29 U.S.C. 1185a and parallel laws, applies to health plans that cover both medical and surgical care and mental health or substance use disorder care. Plans generally treat autism as a mental health condition, because it is diagnosed using the DSM, and they usually manage ABA as a behavioral health benefit. In short, parity means:
- Money limits must match. If a plan has no lifetime or annual dollar limit on substantially all of its medical care, it may not set one on mental health care.
- Cost sharing and visit limits must match. Copays, coinsurance, deductibles and visit or day limits on mental health care cannot be more restrictive than those on most medical care in the same category. These are called quantitative limits.
- Rules and processes must match. Tools like prior authorization, medical-necessity criteria, step requirements and network standards cannot be designed or applied more strictly to mental health care than to comparable medical care. Regulators call these nonquantitative treatment limitations, or NQTLs.
Parity does not require a plan to cover ABA in the first place. It governs how a plan limits mental health benefits it does cover.
Which plans does parity apply to?
| Plan type | Parity applies? | Who enforces |
|---|---|---|
| Large employer plan, fully insured | Yes | Florida DFS and OIR for the insurer; U.S. Department of Labor for the employer plan |
| Self-funded employer plan, more than 50 employees | Yes | U.S. Department of Labor (EBSA) |
| Small employer group plan (generally 2 to 50 employees) | The group parity statute exempts small employers, but small-group insurance that must cover essential health benefits follows parity through those rules | Florida DFS for Florida-licensed insurers |
| Individual (Marketplace) plan | Yes, through essential health benefit rules | Florida DFS for Florida-licensed insurers |
The statute's small employer exemption says it "shall not apply to any group health plan ... for any plan year of a small employer," defined as an employer with an average of at least 2 (or 1, where state law allows) and not more than 50 employees. Florida's autism law has its own rule, too: the coverage it requires may not have dollar limits, deductibles or coinsurance "less favorable" than those for physical illness. Not sure what kind of plan you have? See fully insured vs self-funded plans.
What changed in 2025 and 2026?
The 2024 rule is on hold
Federal agencies issued a detailed parity rule in September 2024. An employer group sued (the case is called ERIC v. HHS). On May 15, 2025, the Departments of Labor, Health and Human Services and the Treasury announced they "will not enforce the 2024 Final Rule or otherwise pursue enforcement actions" for failures that happen before a final court decision, "plus an additional 18 months." That pause covers only the parts of the 2024 rule that are new compared with the 2013 rule. The agencies said that "MHPAEA's statutory obligations, as amended by the CAA, 2021, continue to have effect."
New enforcement priorities in September 2026
On September 8, 2026, the Labor Department's Employee Benefits Security Administration (EBSA) issued Field Assistance Bulletin 2026-03, "Guiding Principles for EBSA's Enforcement of the Mental Health Parity and Addiction Equity Act's Nonquantitative Treatment Limitation Requirements." Key points:
- Plans in general "cannot apply blanket exclusions of treatments for covered MH/SUD conditions," and EBSA "will focus its resources on cases involving blanket treatment exclusions applicable only to MH/SUD benefits."
- Medical necessity and prior authorization guidelines must be available "to participants and beneficiaries upon request."
- "Where there are network adequacy parity issues, EBSA will ensure that plans and issuers consider all available options."
- EBSA "will narrow its enforcement focus areas relating to requests for NQTL comparative analyses."
The bulletin does not mention autism or ABA. It applies to the employer plans EBSA oversees. More federal changes are possible; we will update this page when rules change.
What kinds of ABA limits raise parity questions?
These are common situations where families ask about parity. Whether any one of them breaks the rules depends on how the plan treats comparable medical care, which is why the documents in the next section matter.
- An ABA exclusion in a plan that covers autism. For example, a plan that covers autism diagnosis and other mental health care but excludes ABA, while covering comparable medical treatments. This is the kind of "blanket exclusion" FAB 2026-03 says EBSA will focus on.
- A fixed hour or visit cap that applies only to ABA, when the plan has no similar cap on comparable medical therapies.
- Prior authorization or reauthorization that is stricter for ABA, such as much shorter approval periods or more paperwork than for comparable outpatient medical care.
- An age cutoff written only for ABA.
- Too few in-network ABA providers, leaving families on long waits or paying out-of-network costs.
For hour cuts at reauthorization, see why an ABA authorization gets cut.
What can I ask my plan for?
The medical necessity criteria
The statute says the criteria for medical necessity decisions on mental health benefits "shall be made available by the plan administrator (or the health insurance issuer offering such coverage) in accordance with regulations to any current or potential participant, beneficiary, or contracting provider upon request." It also says the reason for any denial of payment for mental health services shall, on request or as otherwise required, be made available to the participant.
Comparative information on NQTLs
Since 2021, plans must perform and document "comparative analyses of the design and application of NQTLs" and give them to federal regulators on request. For people in employer plans covered by ERISA, the agencies' FAQ Part 45 (April 2, 2021) says participants and beneficiaries "are entitled to comparative information on medical necessity criteria for both medical/surgical benefits and MH/SUD benefits, as well as the processes, strategies, evidentiary standards, and other factors used to apply an NQTL." Plans do not always respond fully, and the rights differ for individual-market and government plans, but asking is reasonable.
A sample request
"I am requesting, for my child [name, member ID], (1) the medical necessity criteria used to review applied behavior analysis, (2) the specific reason for the denial dated [date] and the plan provisions relied on, and (3) the comparative information on how prior authorization and medical necessity review are applied to ABA compared with medical and surgical benefits in the same classification, including any NQTL comparative analysis. Please send these in writing."
Send it in writing, keep a copy, and note the date. If you are mid-appeal, watch your appeal deadlines while you wait.
Who can help if I think my plan is breaking parity rules?
- Employer plans, including self-funded plans: the U.S. Department of Labor's Employee Benefits Security Administration, toll-free 1-866-444-3272.
- Fully insured plans and Florida individual plans: the Florida Department of Financial Services Insurance Consumer Helpline, 1-877-693-5236.
- An independent review after the plan's final internal denial. See external review in Florida.
- A Florida attorney who handles health insurance or ERISA claims, for legal advice on your situation.
See also filing an insurance complaint in Florida.
How Hope Center can help
Our BCBAs write treatment plans with measurable goals and progress data, the kind of documentation plans review. Every plan is reviewed by our clinical director before it goes to insurance. If a plan cuts or denies hours, we explain what the plan said and what information may help in an appeal; the appeal decision belongs to the plan and the reviewers. Start with a free benefits check: see insurance at Hope Center, contact us, or call 561-337-8865.