Original Medicare covers preexisting conditions, while Medicare Part D covers medications for those conditions. Medigap and Medicare Advantage plans generally cover preexisting conditions with some exceptions.

Original Medicare — which includes Part A (hospital insurance) and Part B (medical insurance) — covers preexisting conditions.

Medicare Part D (prescription drug insurance) will also cover the medications you’re currently taking for your preexisting condition.

Keep reading to learn more about which Medicare supplement plans cover preexisting conditions and what situations might prevent coverage.

Medicare supplement plans (Medigap plans) are offered by private companies approved by Medicare. Medigap plans cover some of the costs not covered by original Medicare, such as deductibles, coinsurance, and copayments.

If you purchase a Medigap plan during your open enrollment period, even if you have a preexisting condition, you can get any Medigap policy sold in your state. You cannot be denied coverage, and you will pay the same price as people without preexisting conditions.

Your open enrollment period for Medigap coverage starts the first month you are 65 and are also enrolled in Medicare Part B.

Can you be denied Medigap coverage?

If you apply for Medigap coverage after the open enrollment period, you might not meet medical underwriting requirements and could be denied coverage.

Medicare Advantage plans (Medicare Part C) are offered by private companies that have been approved by Medicare. These plans are bundled to include Medicare Parts A and B, usually Medicare Part D, and often additional coverage such as dental and vision.

You can join a Medicare Advantage plan if you have a preexisting condition unless that preexisting condition is end stage renal disease (ESRD).

Medicare Advantage Special Needs plans

Medicare Advantage Special Needs Plans (SNPs) include Medicare Parts A, B, and D and are only available for people with certain health conditions such as:

  • autoimmune disorders: celiac disease, lupus, rheumatoid arthritis
  • cancer
  • certain, disabling behavioral health conditions
  • chronic cardiovascular disease
  • chronic drug dependence or alcohol use disorder
  • chronic heart failure
  • chronic lung disorders: asthma, COPD, emphysema, pulmonary hypertension
  • dementia
  • diabetes mellitus
  • end stage liver disease
  • ESRD requiring dialysis
  • HIV or AIDS
  • hematological disorders: deep vein thrombosis (DVT), sickle cell anemia, thrombocytopenia
  • neurological disorders: epilepsy, multiple sclerosis, Parkinson’s disease, amyotrophic lateral sclerosis
  • stroke

If you become eligible for an SNP and there’s a local plan available, you can enroll anytime.

If you no longer qualify for a Medicare SNP, you can change your coverage during a special enrollment period. This time period starts when you are notified by your SNP that you’re no longer eligible for the plan and continues for 2 months after coverage has ended.

Original Medicare (Part A and Part B) — covers preexisting conditions. Medicare Part D covers any needed medications for that preexisting condition.

If you have a preexisting condition, consider signing up for a Medigap plan (Medicare supplement plan) policy. Medigap plans cover some of the costs not covered by original Medicare, such as deductibles, coinsurance, and copayments.

Medigap offers an open enrollment period during which you cannot be denied coverage, and you will pay the same price as people without preexisting conditions. You might not be able to get coverage if you enroll outside of your open enrollment period.

If you’re considering a Medicare Advantage plan, depending on your preexisting condition, you may be eligible for a Medicare Advantage SNP.