Enrolling in Part D Prescription coverage is voluntary unless receiving benefits from Medicaid.
If you already have sufficient (creditable) prescription coverage through a group plan or VA benefits then it is not necessary to join a Part D plan.
There are two ways to get Medicare Prescription Drug Coverage.
Prescription Drug Plans (PDP)
including Prescription Drug coverage (MA-PD)
The following costs are associated with Prescription Drug coverage. Your actual costs will depend on usage and plan selection and whether you qualify for Extra Help paying for your Part D costs:
When reviewing PDP plans the major factors affecting monthly premium rates are the deductible and whether any coverage applies in the donut hole.
If you don’t sign up for Prescription Drug coverage when first eligible or have some other creditable coverage you will be charged a late enrollment penalty. In addition you can be penalized anytime you go a period of more than 62 days without creditable coverage. The penalty is calculated by multiplying 1% of the national base premium times the number of months you should have been enrolled but did not.