One of the first questions people ask before starting treatment is whether their insurance will pay for it. Many people simply do not know. In a 2025 national study of adults with a substance use disorder, only about half of those with group-based private insurance knew their insurance covered substance use treatment. Nearly 40 percent said they did not know (Creedon et al.).

This article explains what the federal parity law requires, where coverage problems still happen, and which questions to ask your health plan.

What parity means

The Mental Health Parity and Addiction Equity Act became law in 2008. SAMHSA summarizes it this way: insurance groups that offer coverage for mental health or substance use disorders must make those benefits comparable to general medical coverage. Deductibles, copays, out-of-pocket maximums, and treatment limits for mental health or substance use disorders must be no more restrictive than those for other medical care (SAMHSA).

SAMHSA puts it in plain terms for people with job-based coverage. If your job-based health plan offers mental health benefits, they must be covered equally with other medical and surgical benefits (SAMHSA).

In practice, that means a plan should not, for example, set a much tighter visit limit for outpatient substance use counseling than it sets for comparable medical care.

What parity does not do

Parity is about fairness between types of benefits. It is not a promise that every service is covered, and it has not removed every barrier.

The same 2025 study used national survey data from 2006 to 2014. It found that the parity law was not linked to a statistically significant increase in treatment rates among adults with group private insurance. Fewer than 10 percent of people with a substance use disorder received treatment in a given year. The authors point to barriers that are not about money, including mixed feelings about treatment and not knowing what insurance covers (Creedon et al.).

That last barrier is one you can do something about. Knowing your benefits ahead of time removes one obstacle.

Where coverage problems still happen

A 2022 study interviewed substance use treatment providers in Connecticut, Kentucky, and Wisconsin about their experiences with insurance after parity and the Affordable Care Act. Several patterns came up (Dickson-Gomez et al.):

  • Prior authorization. Providers reported that many treatments required approval from the plan in advance, including buprenorphine. Claims were often denied at first and then approved after an appeal.
  • Medical necessity. Some treatments were denied because the plan did not consider them medically necessary. The authors describe these standards as sometimes applied in ways that work against people with substance use disorders.
  • Networks. Under managed care, providers must be in the plan's network to be paid.
  • Different coverage from plan to plan. Coverage varied widely across state Medicaid programs and private insurance. None of the three states covered every level of care that ASAM recommends.
  • High deductibles. Many marketplace plans had high deductibles, which can mean large out-of-pocket costs.

These findings come from three states and may not match every plan. They are still a useful guide to what to ask about.

Questions to ask your health plan

The number on the back of your insurance card is the usual place to start. These questions can help you understand your coverage before treatment begins:

  • Does my plan cover outpatient substance use treatment, including intensive outpatient and partial hospitalization?
  • Is the program I am considering in network?
  • Which services need prior authorization, and who requests it?
  • What is my deductible, and how much of it have I met this year?
  • What are my copays or coinsurance for these services?
  • Are there limits on the number of visits or days covered?
  • Are medications for substance use disorders covered, and do they need approval in advance?

Write down the date, the name of the person you spoke with, and any reference number for each call. If you get different answers on different calls, those notes help.

If a claim is denied

A denial is not always the final word. SAMHSA notes that if you are having issues with coverage for mental health, drug, or alcohol treatment, you can ask your health insurance company to review its coverage decision again by telling it you would like to appeal (SAMHSA).

The providers in the 2022 study described claims that were denied at first and paid after appeal (Dickson-Gomez et al.). That does not mean every appeal succeeds. It does mean an appeal is worth considering.

A few practical steps:

  • Read the denial letter closely and note the reason given.
  • Ask the plan how to file an appeal and what deadline applies.
  • Ask your treatment team whether they can provide clinical information to support the appeal.
  • Keep copies of every letter, bill, and statement.

Questions worth asking your treatment program

  • Can you help me check my benefits before I start?
  • Will you request any prior authorizations my plan needs?
  • What happens if my plan approves only part of the recommended care?
  • If a claim is denied, can you help with the appeal?
  • What costs should I expect to pay myself?

The short version

Many people with insurance do not know whether it covers substance use treatment. The federal parity law requires that group plans covering mental health and substance use care do so on terms comparable to medical care. That includes deductibles, copays, and treatment limits. Parity does not guarantee every service is covered, and barriers such as prior authorization and medical necessity reviews still exist. Calling your plan with specific questions, keeping notes, and knowing you can appeal a denial are practical ways to protect your access to care.