A common question among those that continue to work beyond age 65 or Medicare eligibility is this;

“Do i sign up for Medicare at all if continue working and have group coverage?”

The answer is: Ask HR or request the employee handbook or policy for employees that are Medicare eligible.
Important to consider how this affects the spouse/dependents whether younger or older. Company benefits vary considerably especially by the numbers, the more employees the more coverage options available including businesses with more than 20 Medicare eligible can offer GROUP Medicare insurance.

Common Case:
Patrick’s company does not offer Group Medicare benefits but he and his wife can continue on the same Group Plan as before, he may pay a little more for his age but it seems like a safer option and what he and wife are used to. Patrick will be 65 in the spring and Gloria is three years younger, both are active and healthy and take no medicines.

Having read the employee handbook it is determined that Patrick will pay $435 a month for he and his wife which is HALF the premium for this High Deductible Group plan, the employer cost shares the other half. The deductible is $7500 with $12000 max-out-of-pocket. Because HD – high deductible this allows Patrick to put away an extra $7200 (2021) in pre-tax not taxable income into a family HSA to be used later in retirement or now. Advantage #2 reduces your taxable income which is HELPFUL when you do retire and begin Medicare Part B. Part B premium is based on your annual income two years earlier. https://www.medicare.gov/your-medicare-costs/part-b-costs

Medicare costs; Part A $0 premium, Part B $148.50 a month (2021 and income adjusted); This is Medicare Original. Then ADD a MA or medigap and/or Part D plan (all are optional)
Gloria would then be finding her own individual plan until she ages into Medicare. This can be very expensive if there are health issues/concerns. Otherwise she can do anything from self-insure to short term medical to membership cost sharing, a lot of considerations when you don’t use the SYSTEM… Gloria’s cost start from $180 a month

Patrick will continue to work until Gloria reaches Medicare age and he reaches full retirement age for his full SSIB. He is going to enroll in Medicare Part A at $0 and wait to enroll in Part B since his group plan is CREDITABLE coverage for Part B, and his wife will enjoy the same health plan until she ages into Medicare. And they are going to max out their HSA for future health care costs.

James 3:13 Who is a wise man and endued with knowledge among you? let him shew out of a good conversation his works with meekness of wisdom.