Because of the huge number of existing pharmacies (and the always increasing number of pharmacies being added to Part D plan networks), most plans no longer distribute printed copies of their Pharmacy Directory (directories can be outdated as soon as printed).
Instead, Medicare Part D plan providers have online tools that you can access from the plan's website.
The Medicare Part D plan's pharmacy search link and the toll-free Member Services telephone number for most Medicare Part D plans can be found by clicking on the plan name or "Benefits & Contact Info" button on the this site PDP-Finder.com and MA-Finder.com plan finder tools.

Both links will take you to a page showing more Part D plan details such as formulary information (number of drugs per tier), cost-sharing, pharmacy search link, basic enrollment information, Star ratings, and the toll-free Member Services number for every Medicare Part D plan.

You can telephone your plan's Member Services department for more information on local network pharmacies or ask the Member Services representative where you can find the link to the plan's Pharmacy Search tool. The toll-free number for Member Services is on your Member ID card or most of your plan's printed information. Alternatively,
When connected with Member Services, be sure to also ask about the cost-sharing price differences between preferred network pharmacies and non-preferred network pharmacies. Or to see a chart of both 30- and 90-day supply cost sharing for preferred network pharmacies and non-preferred network pharmacies, you can click the Rx$ button under the plan name on our PDP-Finder.com plan finder.