Most insurance plans do cover rehab. Federal parity law requires health insurers to treat addiction and mental health care the same way they treat any other medical condition, so coverage itself is rarely the sticking point. The real questions are which levels of care your plan will pay for (detox, residential, outpatient) and how much you will owe out of pocket once deductibles and copays are figured in. Your specific benefits depend on your plan, your provider, and whether the treatment center is in network.