Most insurance plans do cover rehab. Federal parity law requires health plans to treat addiction and mental health care the same way they treat any other medical condition, so a policy that covers surgery or diabetes care generally has to cover treatment for a substance use disorder too. The real questions are more specific. Which levels of care does your plan pay for, and what will you or your loved one owe out of pocket? Those answers depend on the individual policy, and they are worth checking carefully before treatment begins.