Can Medicare Part D retail drug prices change during the year?

Yes. The retail prices for your Medicare Part D formulary drugs can change throughout the plan year (often increasing slightly) - and retail drug prices can vary pharmacy-to-pharmacy - mid-year increases in your medication’s negotiated retail price will affect your coverage costs and how quickly you move through your drug plan coverage phases, even though you are most likely locked into your Medicare plan for the entire year.

And the bad news:  As retail prices increase for your drugs, your Part D coverage and out-of-pocket costs can change from what you predicted when you chose your Medicare Part D drug plan last November or December - meaning, with mid-year drug price increases, you may no longer be enrolled in the most economical Medicare prescription drug plan - and you may not be able to change plans for the remainder of the year.

See our FAQ for more information:
How do increases in retail drug prices affect my Medicare Part D drug plan coverage?


Question:  Can I find the definite retail drug price?

Probably not.  Retail drug prices fluctuate all the time and a "definite" retail drug price at a specific pharmacy is difficult to determine.  The federal government's Medicare.gov Plan Finder website often provides the most accurate retail cost information across all Medicare plans (in our opinion), however, any retail drug pricing information (from the government or from a plan) is only an estimate.

Basically retail drug prices can: change every week (or more), change from pharmacy to pharmacy (weekly), vary between preferred and standard pharmacies, and retail prices can vary even between a Medicare drug plan's preferred pharmacies. 


Tip:  Viewing average retail drug prices shown in our the drug finder Drug Finder.

As another source for retail drug price information, we show the average negotiated retail drug price in the far right column of our the drug finder DrugFinder comparison chart.

The retail drug prices shown are averaged across all pharmacies in this Medicare drug plan's Service Area.  Again, these average negotiated retail drug prices can vary pharmacy-to-pharmacy (so CVS retail prices may not be the same as prices at Walmart or Walgreens) and retail prices can change week-to-week.

Also, please note that the average negotiated retail drug price can vary state-to-state as you travel with your Medicare Part D plan.

Here is an older example of our on this site Drug Finder showing how the retail price of a popular generic medication can vary between Medicare Part D plans (the estimated cost using a Drug Discount Card is shown at the top of the the drug finder table).  You can see in this example that retail drug prices for this common generic (back in 2020) varied from $3 to $38.70.

(Note: The plan with the $3.00 average retail drug price shows a copay of $4.00.  You will not pay more for the drug than your retail cost, so in this example, you would pay $3.00 not the $4.00 copay.)

(Click on the link to see current plan year data)

You can see in this 2025 example that retail drug prices for this same common generic now vary from $1.49 to $26.99.

(Note: As before, see that the Medicare Part D plan with the $4.28 average retail drug price shows a copay of $17.00.  You will not pay more for the drug than your retail cost, so in this example, you would pay $4.28 not the $17.00 copay.)