Private carriers offer Part C plans, also known as Medicare Advantage Plans, which offer all the benefits covered under Original Medicare (parts A and B) and more. You can select from HMOs, PPOs, Private Fee-for-Service, and Medicare Medical Savings Account (MSA) Plans. In order to join the Part C Plan, you need to be first enrolled in Medicare Parts A and B. Many offer prescription drug coverage, hearing, vision and/or dental coverage.