An Original Medicare Plan, according to the Centers for Medicare and Medicaid (CMS) is defined as:
A fee-for-service health plan that lets you go to any doctor, hospital, or other health care supplier who accepts Medicare and is accepting new Medicare patients. You must pay the deductible. Medicare pays its share of the Medicare-approved amount, and you pay your share (coinsurance). In some cases, you may be charged more than the Medicare approved amount. The Original Medicare Plan has two parts: Part A (Hospital Insurance) and Part B (Medical Insurance).
(source: Medicare.gov)
If you have Original Medicare, you can add a stand-alone Part D plan (PDP) for your prescription drug coverage. You can review and compare plans available using our stand-alone Medicare Part D Plan Finder or PDP-Finder (choose your state to begin).