Medicare’s Six Protected Classes Explained

November 14, 2023

In 2003, Congress passed the Medicare Modernization Act (MMA), which created an outpatient prescription drug benefit in the Medicare program. Known as Part D, the prescription benefit is operated exclusively through private insurance plans that contract with Medicare. To ensure that beneficiaries have coverage for the drugs they need Part D plans are required to cover at least two drugs in each therapeutic class. A therapeutic class is a group of medications that are used to treat the same condition. 

What are the Six Protected Classes?

The Centers for Medicare and Medicaid Services (CMS) – which implemented the new Medicare drug benefit – acknowledged that, in some cases, Medicare beneficiaries may need access to more than two different drugs within a therapeutic class. CMS identified six “categories and classes of clinical concern,” commonly known as the “six protected classes,” and required Part D plans to cover “all or substantially all drugs” within each of the classes. These six protected classes include: anticonvulsants, antidepressants, antineoplastics, antipsychotics, antiretrovirals, and immunosuppressants. The antineoplastics category includes many oral chemotherapy drugs.

ACS CAN Position

ACS CAN opposes policy changes that would limit beneficiary access to prescription drugs in the classes of clinical concern (e.g., the “six protected classes”) for a variety of reasons.