When you turn 65, you become eligible to sign up for Medicare. You can choose from a variety of plans and you're also given the opportunity to select a Medicare Advantage plan often referred to as Medicare Part C.

Private companies offer Medicare Advantage plans and include Health Maintenance Organizations (HMO), Preferred Provider Organizations (PPO), Private Fee-for-Service Plans (PFFS) and Special Needs Plans (SNPs). You'll pay a separate premium for Medicare Advantage in addition to your traditional Medicare coverage.

Coverage options
Depending on your plan, you'll find different coverage options for prescription drugs, referrals, primary care physicians and network choices.

  • HMO: Prescription drugs are covered with most HMO plans but you'll want to ask your provider to be sure. Keep in mind when choose your policy that if you want Medicare Part D you must join an HMO plan that offers prescription drug benefits. When it comes to choosing a doctor, HMOs require you to seek health care from a doctor or hospital within the network. Most of those with an HMO will be required to choose a primary care doctor. If you want to see a specialist, you'll need a referral with an HMO plan.
  • PPO: Similar to HMO, PPO plans typically cover prescription drugs. However, if you join a PPO plan that doesn't offer coverage, you won't be permitted to join a Part D plan offered by Medicare. When choosing a health care provider or doctor with a PPO you have more flexibility to see who you prefer. There's no need to choose a primary care doctor when you have a PPO plan. Most don't need a referral to see a specialist if they are covered by a PPO plan but costs are typically lower if you see one that's listed on the plan.
  • PFFS: Prescription drugs may be covered under a PFFS plan but if they aren't you can join a Medicare Prescription Drug Plan. When choosing a health care provider under this type of plan, you can go to anyone you prefer as long as they are a Medicare-approved physician and agree to treat you. You are not required to choose a primary care doctor or need a referral for a specialist if you have a PFFS plan. 
  • SNPs: Any SNP will provide Medicare beneficiaries with prescription drug coverage. SNP beneficiaries can generally only receive services from doctors or hospitals in the Medicare SNP network except for cases such as End-Stage Renal Disease and out-of-area dialysis. Most of those with an SNP are required to choose a primary car doctor to have a care coordinator to assist with your health care. You'll also need referrals to see specialists under this type of plan with some exclusions including certain services such as yearly mammograms or an in-network pap test and pelvic exam.