I am 68 still working , have not started social security and I'm covered for medical and prescriptions through my job. I am working on filling in the calculator but may need to start SS due to financial issues. If I do, so I need to start Medicare A,B,C and D right away.
You couldn't start drawing Social Security benefit payments without enrolling in Part A of Medicare, but you wouldn't be forced to sign up for any of the other parts of Medicare. As long as you have qualified health coverage through your current employer, you can generally enroll in other parts of Medicare when you retire without being required to pay a penalty for late enrollment (https://www.ssa.gov/planners/retire/justmedicare.html#h5).