No, once you are enrolled in Medicare (including Part A or Part B), you are no longer eligible to contribute to a Health Savings Account . 

However, the good news is that you can still use existing funds in your HSA to pay for qualified medical expenses, including some Medicare costs, even after you enroll in Medicare. 

Here are some important points to understand:

• No new contributions: You (and your employer) must stop making contributions to your HSA starting the month your Medicare coverage begins.
• Backdating and penalties: If you delay Medicare enrollment past age 65, and your enrollment is backdated (which can happen, for example, if you enroll six months after your full retirement age and receive six months of retirement benefits backpay), any HSA contributions made during that retroactive period are considered excess contributions and may be subject to a 6% excise tax.
• Using existing funds: You can continue to use your existing HSA funds tax-free for a variety of qualified medical expenses, including:
  • Medicare Part B premiums.
  • Part D premiums.
  • Medicare Advantage plan premiums.
  • Deductibles, copays, and coinsurance.
• Medigap Premiums: HSA funds cannot be used to pay for Medigap premiums.