Medicare Rehab Coverage

Does Medicare cover rehab?

Yes. Part A covers inpatient substance-use treatment, Part B covers outpatient therapy and screening, and Part D covers medications like buprenorphine. If you have a Medicare Advantage plan instead of Original Medicare, it must cover at least what Original Medicare covers, though the network and prior-authorization rules can look different.

Age isn't the only path to Medicare — people under 65 who qualify through disability can have the same coverage, which matters since addiction and disability often intersect.

What's covered

Inpatient hospital-based treatment, outpatient therapy and counseling, substance use screening, and medication-assisted treatment medications are all covered, subject to the usual Medicare deductibles and coinsurance.

Annual substance use screenings and brief counseling are also covered under Part B at no cost in many cases, which is worth knowing even before a crisis happens.

How many days does Medicare actually cover?

This is the part that trips people up. The “100 days” number people search for usually refers to skilled nursing facility care after a hospital stay — not addiction treatment.

For inpatient hospital-based substance use or psychiatric treatment under Part A, coverage instead follows the standard hospital benefit-period structure, where cost-sharing increases the longer a stay runs, rather than a flat day count. Ask the treatment center's billing staff to walk through exactly how your benefit period applies before a long stay.

The fine print

Deductibles and coinsurance change annually and depend on which benefit period you're in, so the exact dollar amounts aren't something to rely on secondhand — confirm current numbers directly with Medicare or the facility.

The main thing to know going in: longer stays generally mean more cost-sharing, not less, and specialized inpatient psychiatric care has its own lifetime limits that are worth asking about directly.

How to actually get Medicare to pay

Use a Medicare-certified or Medicare Advantage in-network provider, make sure a physician documents medical necessity for the level of care you're entering, and — if you're on a Medicare Advantage plan — get any required prior authorization before admission. Skipping that last step is one of the most common reasons claims get denied.

Why Medicare might deny a claim

Common reasons include missing documentation of medical necessity, using an out-of-network provider under a Medicare Advantage plan, exceeding the days or services covered in a benefit period, or requesting a service Medicare doesn't classify as covered treatment. Denials can be appealed, so don't treat a first denial as final.

If you're dual-eligible for Medicare and Medicaid

A significant number of Medicare beneficiaries also qualify for Medicaid based on income, and being dual-eligible can dramatically reduce what you owe out of pocket, since Medicaid often picks up Medicare's deductibles and coinsurance.

If you're not sure whether you qualify for Medicaid alongside Medicare, it's worth checking — a lot of people assume Medicare alone is their only option and never look into it.

Supplemental coverage (Medigap)

A Medigap policy, if you have one, can cover some or all of the coinsurance and deductibles that apply during addiction treatment under Original Medicare. It doesn't change what Medicare covers, but it changes how much of the remaining cost lands on you.

Finding a provider

Look for Medicare-accepting centers and confirm whether they take Original Medicare, your specific Advantage plan, or both. If you also have Medicaid or supplemental coverage, ask the center how the two work together — dual eligibility can significantly lower your out-of-pocket cost.