Mental health parity, explained

Mental health parity is the federal rule that a health plan may not make mental health or substance use disorder (MH/SUD) benefits harder to get than medical or surgical benefits. The governing statute is the Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act of 2008 (MHPAEA). This page explains what it requires, what it does not do, who it reaches, and where to take a concern. Every statement below is drawn from the CMS and Federal Register pages listed under Sources, as read on October 22, 2026. For analysis of enforcement trends, see our parity enforcement report and the policy and payers section.

What MHPAEA requires

CMS summarizes the law this way: MHPAEA “generally prevents group health plans and health insurance issuers that provide mental health or substance use disorder (MH/SUD) benefits from imposing less favorable benefit limitations on those benefits than on medical/surgical benefits.”

In practice the statute and its regulations compare three things between MH/SUD and medical/surgical benefits:

1. Financial requirements — deductibles, copayments, coinsurance and out-of-pocket maximums.
2. Quantitative treatment limitations (QTLs) — numerical limits such as visit limits and day limits.
3. Nonquantitative treatment limitations (NQTLs) — limits that are not numbers, such as prior authorization, medical management, step therapy, network composition standards and out-of-network reimbursement methodologies.

The test is applied separately within six classifications of benefits: inpatient in-network, inpatient out-of-network, outpatient in-network, outpatient out-of-network, emergency care, and prescription drugs. Sub-classifications are permitted for office visits (separate from other outpatient services) and for plans with multiple tiers of in-network providers.

Term	What it means	Example
Financial requirement	A cost the enrollee pays	$40 copay per visit; 20% coinsurance
Quantitative treatment limitation	A numerical limit on benefits	20 outpatient visits per year
Nonquantitative treatment limitation	A non-numerical limit on scope or duration	Prior authorization; step therapy; network admission standards
Classification	One of six benefit buckets compared separately	Outpatient, in-network
”Substantially all / predominant” test	The standard for comparing financial requirements and QTLs across a classification	A copay may apply to MH/SUD only if it is the predominant copay applied to substantially all medical/surgical benefits in that classification
Comparative analysis	The written analysis a plan must prepare for each NQTL it applies to MH/SUD benefits	Documenting how prior-authorization criteria for psychotherapy compare with those for physical therapy

Three rules from the 2013 regulation, as CMS describes them:

• Cumulative financial requirements must be combined. Deductibles and out-of-pocket limits in a classification must combine medical/surgical and MH/SUD benefits; a separate mental-health deductible is not permitted.
• No MH/SUD-only limits. MHPAEA “prohibits separate financial requirements and treatment limitations that apply only to MH/SUD benefits.”
• NQTLs must be comparable as written and in operation. A plan may not impose an NQTL on MH/SUD benefits in a classification unless the “processes, strategies, evidentiary standards, or other factors” used are comparable to, and applied no more stringently than, those used for medical/surgical benefits in the same classification. The 2013 final regulation removed an earlier exception that had allowed differences based on “recognized clinically appropriate standards of care.” Geographic limits, facility-type limits and network adequacy standards are all subject to the NQTL rules.

What MHPAEA does not do

• It does not require coverage. CMS is explicit: the law “does NOT require group health plans or health insurance issuers to cover MH/SUD benefits.” The coverage mandate for individual and small-group plans comes from the Affordable Care Act’s essential health benefit (EHB) rules, which treat MH/SUD services as one of ten EHB categories for non-grandfathered plans.
• It does not set prices or reimbursement rates. Parity compares how limits are designed and applied; it does not fix what a plan pays a clinician, although out-of-network reimbursement methodology is an NQTL that must be comparable.
• It does not reach Medicare. CMS notes that Medicare, Medicaid and CHIP “are not group health plans or issuers of health insurance.” Medicaid managed care plans, CHIP and Medicaid alternative benefit plans are brought under certain MHPAEA requirements through the Social Security Act and a 2016 final rule (see Sources). Medicare is not.
• It does not directly reach small employers. CMS states MHPAEA “does not apply directly to small group health plans,” although its requirements are applied indirectly through the EHB rules. A small employer is generally one with 1 to 50 employees, with a state option to extend the definition to 1 to 100.

Who regulates which plan

Which agency hears a complaint depends on how the coverage is arranged. CMS describes the split as follows:

Coverage type	Regulator
Insurance purchased from an issuer (insured group plans and the individual market)	The state insurance department
Private employer plan that pays claims itself (self-funded)	U.S. Department of Labor (EBSA)
Non-federal governmental plan (state and local government employers)	U.S. Department of Health and Human Services (CMS)
Medicaid managed care, CHIP, Medicaid alternative benefit plans	State Medicaid agency, under the 2016 CMS final rule

CMS’s advice: “Contact your employer’s plan administrator to find out if your group coverage is insured or self-funded and to determine what entity or entities regulate your benefits.” Some states have parity requirements stricter than the federal floor; the state trackers on this site log state-level parity legislation and enforcement actions as they are reported.

The 2021 comparative-analysis requirement

Section 203 of Title II of Division BB of the Consolidated Appropriations Act, 2021 (enacted December 27, 2020) amended MHPAEA to require plans and issuers that offer both medical/surgical and MH/SUD benefits and impose NQTLs on MH/SUD benefits “to perform and document their comparative analyses of the design and application of NQTLs.” Beginning 45 days after enactment, those analyses must be made available to the Departments or applicable state authorities upon request. This is the documentation regulators ask for first when they examine a plan’s prior-authorization, concurrent-review or network practices.

The 2024 final rules

On September 9, 2024, HHS, Labor and the Treasury released new final rules implementing MHPAEA; they were published in the Federal Register on September 23, 2024 (89 FR, document 2024-20612) with an effective date of November 22, 2024. According to the rule’s abstract and CMS’s summary, the rules:

• amend the NQTL standard to prohibit plans and issuers from using NQTLs that place greater restrictions on access to MH/SUD benefits than on medical/surgical benefits;
• require plans and issuers to collect and evaluate relevant data on the impact of NQTLs on access, and to take reasonable action where the data show material differences;
• codify the CAA 2021 comparative-analysis requirement and set content requirements and timeframes for responding to requests for those analyses, including for network composition, out-of-network reimbursement rates, and medical management and prior authorization NQTLs;
• prohibit the use of discriminatory information, evidence, sources or standards that systematically disfavor access to MH/SUD benefits when designing NQTLs;
• implement the sunset of the opt-out election previously available to self-funded non-federal governmental plans.

Rules of this scope are routinely litigated and their applicability dates can be adjusted by the Departments. This page states what the published rule says; it does not track enforcement posture or court actions. Check the Federal Register document and the Departments’ MHPAEA pages for the current status before relying on a specific provision, and see our enforcement report for analysis.

How to raise a parity concern

1. Identify the plan type. Ask the employer’s plan administrator whether the coverage is insured or self-funded, or check the plan documents. This decides the regulator.
2. Gather the paper. Keep the denial letter or policy, the plan’s summary plan description, and the comparable medical/surgical rule if you can find it. For a clinician, note the CPT code, the service, and the limitation applied.
3. Ask the plan. Request the plan’s criteria for the limitation and, where applicable, the NQTL comparative analysis. MHPAEA imposes disclosure requirements on plans and issuers.
4. Contact the regulator. CMS publishes this route for parity concerns: “contact our help line at 1-877-267-2323 extension 6-1565 or at phig@cms.hhs.gov. You may also contact a benefit advisor in one of the Department of Labor’s regional offices at www.askebsa.dol.gov or by calling toll free at 1-866-444-3272.” For insured coverage, the state insurance department is the primary regulator.
5. Use the plan’s appeal rights in parallel. A parity complaint does not pause claim-appeal deadlines.

Statutory text

• Private employer plans: ERISA section 712, codified at 29 U.S.C. § 1185a.
• Insurers and non-federal governmental plans: Public Health Service Act section 2726, codified at 42 U.S.C. § 300gg-26.
• The Internal Revenue Code contains a parallel provision for group health plans (26 U.S.C. § 9812).

Sources

All sources were read on October 22, 2026.

• Centers for Medicare & Medicaid Services, “The Mental Health Parity and Addiction Equity Act (MHPAEA),” cms.gov. Source for the statutory summary, the six classifications, the 2013 regulation provisions, applicability, regulator split, the Medicaid/CHIP note and the help-line contacts quoted above.
• Departments of the Treasury, Labor and Health and Human Services, “Requirements Related to the Mental Health Parity and Addiction Equity Act,” final rules, Federal Register, published September 23, 2024, effective November 22, 2024, federalregister.gov, document 2024-20612. Source for the 2024 rule summary.
• Final regulation implementing MHPAEA, Federal Register, November 13, 2013 (78 FR 68240), gpo.gov PDF, as linked from the CMS page.
• CMS, “Medicaid and Children’s Health Insurance Programs; Mental Health Parity and Addiction Equity Act of 2008,” final rule, March 30, 2016, federalregister.gov, as linked from the CMS page.
• 29 U.S.C. § 1185a and 42 U.S.C. § 300gg-26, Legal Information Institute, Cornell Law School.

This page is educational. It is not legal advice and does not create an attorney-client relationship. Coverage disputes turn on the plan’s documents and the regulator’s reading of them; consult the plan, the regulator or counsel before acting.