Mental Health Parity (MHPAEA): how to enforce it when your plan won't

Parity is the law - and it is broken on purpose

The Mental Health Parity and Addiction Equity Act (MHPAEA), codified at 29 USC § 1185a for ERISA group plans, 42 USC § 300gg-26 for plans regulated under the Public Health Service Act, and 26 USC § 9812 for the Internal Revenue Code, requires that any group or individual health plan that offers mental health or substance use disorder (MH/SUD) benefits do so on terms no more restrictive than those applied to comparable medical/surgical (M/S) benefits. That means: same financial requirements (deductibles, copays, coinsurance), same quantitative treatment limitations (visit caps, day caps), and same non-quantitative treatment limitations (prior authorization, step therapy, network adequacy, medical necessity criteria, reimbursement methodology).

Despite being law since 2008, parity violations remain rampant. Plans cap therapy visits at 20 per year while imposing no analogous cap on chiropractic. They run concurrent utilization review on every day of a psychiatric admission while leaving comparable medical admissions alone. They reimburse network therapists at rates so low that providers leave the network, creating an effective exclusion. The 2021 Consolidated Appropriations Act tried to fix this by adding 29 USC § 1185a(a)(8), requiring plans to maintain and disclose on request a written comparative analysis of every non-quantitative treatment limitation (NQTL) applied to MH/SUD benefits.

The two flavors of parity violation

Quantitative treatment limitations (QTLs)

Numerical caps on benefits: visit limits, day limits, dollar limits, deductibles, copays. The parity test under 29 CFR § 2590.712(c)(2) is the "substantially all/predominant" test: a QTL cannot apply to MH/SUD benefits in a classification unless it applies to substantially all (defined as at least two-thirds of) M/S benefits in the same classification, and then only at the predominant level (the level that applies to more than half of M/S benefits subject to the limitation).

QTL violations are easier to spot. If your plan caps outpatient therapy visits but does not cap office visits to physical therapy, internal medicine, or any other M/S specialty, the therapy cap is suspect.

Non-quantitative treatment limitations (NQTLs)

Everything else the plan does to limit benefits: prior authorization, concurrent review, retrospective review, step therapy, fail-first, formulary tiering, medical necessity standards, network admission criteria, reimbursement methodology, geographic restrictions, exclusions, and standards for provider participation. 29 CFR § 2590.712(c)(4) requires that any NQTL imposed on MH/SUD benefits be no more stringent in design or application than the comparable NQTL imposed on M/S benefits.

NQTLs are where most modern violations hide because they look neutral on paper. The pattern is: a plan applies a "medical necessity review" to both inpatient psych and inpatient medical/surgical care - facially equal - but in practice approves 95% of medical/surgical admissions and 50% of psych admissions because the criteria are stricter.

Step 1: Demand the comparative analysis

Under 29 USC § 1185a(a)(8)(A), every plan imposing an NQTL on MH/SUD benefits "shall perform and document their comparative analysis" of (i) the plan's NQTL design and (ii) the application of the NQTL in operation. Under § 1185a(a)(8)(B), the plan must make that analysis available to the DOL or HHS on request and to "any participant or beneficiary upon request."

Send a written request to the plan demanding production of the comparative analysis, citing 29 USC § 1185a(a)(8). The Tri-Agency (DOL/HHS/Treasury) self-compliance tool published at dol.gov/agencies/ebsa/laws-and-regulations/laws/mental-health-parity identifies the six elements the analysis must contain:

1. A clear description of the specific NQTL, plan terms, and policies at issue.
2. Identification of the M/S and MH/SUD benefits to which the NQTL applies.
3. Identification of the factors used in designing the NQTL.
4. Evidentiary standards used to evaluate those factors.
5. A comparative analysis demonstrating that the NQTL is applied no more stringently to MH/SUD than to M/S benefits, both as designed and in operation.
6. The specific findings and conclusions reached.

Most plans cannot produce a real analysis on demand because they never did one. The 2023 DOL Report to Congress on MHPAEA found that "no plan or issuer subjected to the comparative analysis review process … was found to be in compliance" on the first review. That is your leverage.

Step 2: Frame the appeal as a parity violation

In addition to the standard medical-necessity arguments, your appeal should:

• Identify the specific NQTL the plan applied (e.g., "the plan required prior authorization after the eighth psychotherapy visit").
• Identify a comparable M/S benefit that is not subject to the same NQTL (e.g., "the plan does not require prior authorization for any chiropractic visit, regardless of number").
• Cite 29 USC § 1185a and 29 CFR § 2590.712 (or 45 CFR § 146.136 for individual market and non-federal governmental plans) and demand application of parity.
• Demand production of the comparative analysis under § 1185a(a)(8).
• Cite the DOL/HHS/Treasury joint guidance and any state parity enforcement bulletin that applies.

Step 3: Escalate aggressively

Parity is a regulatory enforcement priority. The 2021 CAA gave DOL authority to publicly name violators and to require plan-wide remediation. After internal appeal:

• External review: file under 45 CFR § 147.136 - the IRO must apply parity standards. See our external review guide.
• DOL EBSA at 1-866-444-3272 for ERISA plans.
• CMS CCIIO for individual market plans and non-federal governmental plans.
• State insurance commissioner. Many states have additional parity laws (NY Insurance Law § 4303, CA Health & Safety Code § 1374.72, IL Public Act 102-0579) that go further than MHPAEA. See our commissioner complaint guide.
• State attorney general. The New York, California, Massachusetts, and Pennsylvania AGs have brought parity enforcement actions resulting in nine-figure settlements.

Specific parity issues by service

Residential treatment for SUD

Plans frequently apply ASAM levels-of-care criteria more stringently than skilled-nursing-facility admission criteria for equivalent M/S placements. The DOL and HHS 2024 final rule (published April 2024) clarified that NQTL design must consider both factors and evidentiary standards on a comparative basis.

ABA therapy for autism

Plans that cap ABA hours, exclude ABA after a certain age, or require concurrent review on every authorization while applying no analogous limits on PT or OT for developmental delay are suspect. Many state laws (CA, NY, IL, TX, FL) independently mandate ABA coverage with specified hour minimums.

Eating disorder treatment

Plans that exclude residential treatment for anorexia nervosa while covering inpatient medical stabilization for any comparable medical condition violate parity. Wit v. United Behavioral Health (N.D. Cal. 2019; partially reversed and remanded 9th Cir. 2023) developed extensive findings on residential criteria.

Medication-assisted treatment (MAT) for opioid use disorder

Plans that exclude or limit buprenorphine, methadone, or naltrexone, or that impose prior authorization more stringent than for analogous M/S medications, violate parity. The 2024 rule specifically addresses MAT NQTLs.

Common mistakes

• Appealing only on medical necessity. A pure medical-necessity appeal misses the strongest argument. Pair it with a parity demand.
• Not requesting the comparative analysis. Without a § 1185a(a)(8) request, the plan can stay silent on its NQTL methodology.
• Skipping state law. State parity statutes often add private rights of action that MHPAEA does not.
• Not naming the comparator. Always identify a specific M/S benefit that is treated less restrictively.

Frequently asked questions

See also: ERISA appeals, external review and IRO, sample appeal letter library, and medical-necessity denial codes.