Yes. If you are receiving Medicare benefits, you can withdraw from your remaining health savings account (HSA) balance to pay for healthcare expenses and pay for your Medicare premiums (does not apply to Medigap or Medicare Advantage premiums).
However, you will not be able to continue contributions to your account once you are enrolled in Medicare. This includes pre-65 disability Medicare.
When you are no longer enrolled in the Consumer-driven health plan (CDHP), you will have to pay for any monthly administrative HSA fees previously paid by the state.