Medicare Glossary

Open Enrollment Period (OEP)

For Medicare Advantage, the period from January 1–March 31 each year when enrolled MA beneficiaries can switch to a different MA plan or return to Original Medicare (with Part D if desired). Changes take effect the first of the following month.

Also known as: OEP, Medicare Advantage OEP

Out-of-Network

Providers, facilities, or suppliers that do not have a contract with your health plan. Using out-of-network providers often costs more. Some Medicare Advantage plans (like PPOs) allow out-of-network use at higher cost; others (like HMOs) generally do not.

Out-of-Pocket Maximum

The most you will have to pay for covered services in a plan year. After you reach this limit, your plan pays 100% of covered costs. Medicare Advantage plans must have an out-of-pocket maximum; Original Medicare does not have one.

Also known as: Out-of-pocket limit, MOOP