The main reason to delay Medicare coverage at age 65 is if you are not retired and still have comprehensive coverage from your employer.
Another reason is to continue funding a Health Savings Account (HSA). Once you enroll in Medicare, you are no longer eligible to contribute to an HSA.
It is important to consult your employer or union benefits administrator to understand how your insurance works before making the decision to enroll or defer Parts A and B. Some employer coverage may require that you enroll in Parts A and B in order to maintain full coverage with your employer.
In order to defer both Medicare parts A and B, one must: