The specific list of prescription drugs covered by your Part D plan (known as the formulary) will vary depending on both the provider and plan options. However, all plan formularies are required to include coverage for protected class medications.
There are six protected class medications that all Part D plans must include coverage for:
Antidepressants
Antipsychotics
Anticonvulsants
Immunosuppressants
Antiretrovirals
Antineoplastics (except in limited circumstances)
Beyond these protected medications, each insurance company has its own list of what is covered. Your advisor can help you find a plan that covers most or all of your recurring monthly prescriptions.