Parity Law: Your Plan Has to Cover This Like Anything Else
The Mental Health Parity and Addiction Equity Act says something simple: if a plan covers mental health and substance use treatment, it cannot impose stricter limits on that care than on medical and surgical care. Enforcement has been the weak point, which makes knowing the rule genuinely useful — a plan that will not fix a violation on request frequently fixes it when named as a parity issue.
What must be comparable
- Financial requirements: copays, coinsurance, deductibles and out-of-pocket maximums.
- Quantitative limits: number of visits or days covered.
- Non-quantitative limits: prior authorization, step therapy, medical necessity criteria, provider admission standards and network adequacy. This last category is where most violations live.
Signals worth challenging: therapy visits capped when medical visits are not; prior authorization for routine therapy when routine medical visits need none; a review after every few sessions with no equivalent for physical therapy; a mental health network so thin that nobody is available within a reasonable distance or time; reimbursement rates so low that no local provider participates. Each of these is a plausible non-quantitative parity problem.
The document that gives you leverage
You have the right to request the plan's medical necessity criteria and its comparative analysis showing how a given limit is applied to mental health versus medical benefits. Plans are required to be able to produce this. Requesting it in writing frequently changes the conversation on its own, because assembling it is work and many limits do not survive being written down.
What parity does not do
It does not require a plan to cover mental health at all — though most plans must, since it is an essential health benefit on ACA-regulated plans. It does not set a rate. It does not force a specific treatment to be covered. It only requires that the terms be no more restrictive than the medical side.
How to complain, and to whom
- Appeal internally, in writing, using the word parity and citing the specific comparison.
- Request the comparative analysis for the limit in question.
- Escalate: to your state insurance department for state-regulated plans, or to the US Department of Labor for employer self-funded plans. Which one depends on your plan type — ask HR whether the plan is fully insured or self-funded.
- Pursue external review if the internal appeal fails.
Frequently Asked Questions
Does parity apply to my plan?
It applies to most employer plans and to ACA individual and small group plans. Some categories, such as certain retiree-only arrangements, are treated differently.
Does it apply to substance use treatment?
Yes — substance use disorder benefits are explicitly covered by the same requirements.
My plan says my therapy is no longer medically necessary. Is that legal?
Medical necessity review is permitted, but the criteria and the frequency of review must be comparable to the medical side. Request the criteria and the comparative analysis, then appeal.
Does parity guarantee I can find a therapist?
Not directly, but network adequacy is a non-quantitative limit subject to parity, which is the basis for challenging a network that cannot produce an appointment.
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