Medicare Part A
With employer coverage, the easy option is to enroll in Medicare Part A. Your premiums will be $0 if you’ve worked in the U.S. for least 10 years. Part A can adjust to reduce your costs if you need a hospital stay. The exception is if you’re giving to a health savings account (HSA) plan and you intend to keep contributing, don’t enroll in Part A.
Medicare Part B
Part B works differently than Part A. You’ll pay a monthly premium that’s based on your income. Some people delay enrollment for Part B and Part D, and this saves them money on premiums. Since your employer insurance already has outpatient benefits, you may not need to pay those premiums for Parts B and D.
Delaying enrollment for Medicare Part B makes your employer plan “creditable coverage” — so you can sign up without having to pay a late fee when you’re ready to retire.