End Medicare penalty, Have Medicare when SS is collected

Allow individuals who have or pay for health insurance as a retiree, ,
Be allowed to postpone Medicare coverage without penalty .
When they choose Medicare or need it, they will pay the new premium cost at the time they sign on . Most Federal employees have insurance and pay thru retirement. Why is there a penalty ,if they choose to delay duplicated insurance coverage.
Allow individuals to wait till they collect Social security , and the cost will be deducted at that time, at whatever the premiums are in the year they collect SS.
The government changed the retirement age , yet didn’t match the SS age change