Medicare drug coverage arrives in one of two ways: bundled into a Medicare Advantage plan, or bought separately as a stand-alone Part D plan sitting beside Original Medicare. The second is the one this page is about, and it is also the one this site can measure, because CMS counts it separately for every state.
What separates it from the bundled kind
A stand-alone plan covers drugs and nothing else. It is generally bought by people who kept Original Medicare, often alongside a supplement policy, because Original Medicare on its own carries no outpatient drug benefit. The bundled alternative folds the same coverage into a Medicare Advantage plan, which is why the two counts move in opposite directions: in states where most people moved to Advantage, far fewer hold a stand-alone plan.
The count, state by state
Every state page on this site carries the number of people in that state who bought drug coverage as a stand-alone Part D plan, taken from CMS's own Medicare Monthly Enrollment file with the field and the date it was read. Read beside the same state's Advantage and Original Medicare counts, it shows the shape of the local market in a way no plan listing does: the stand-alone route is the normal one in some states and a minority choice in others.
The penalty is the part worth knowing in advance
Medicare attaches a late enrolment penalty to drug coverage for people who go without creditable coverage for long enough after becoming eligible, and the penalty is permanent rather than a one-off. That is the single fact about Part D most worth knowing before the decision rather than after it, because the cost of waiting is not recoverable. Medicare publishes how the penalty is worked out, and the page is linked below.
Questions people ask about stand-alone prescription drug plans
Do I need a stand-alone plan if I have Medicare Advantage?
Usually not, because most Medicare Advantage plans include drug coverage. Medicare's own pages set out when the two can and cannot be combined.
How many people actually buy one?
This site publishes the count for every state from CMS's enrollment file, alongside how many are in Advantage and how many stayed in Original Medicare.
What happens if I skip drug coverage?
Medicare may add a permanent late enrolment penalty once you go long enough without creditable coverage. It does not go away later.
Does this site recommend a drug plan?
No. It names none and quotes no premiums. Which plan covers your medicines is a question for Medicare's plan finder, which asks for the medicines.