Yes, but, it depends on when the formulary change is made and if you are affected by the change.  Your Medicare drug coverage can change year-to-year and can change during the plan year - and your plan is required to provide you with notifications of some changes depending on when the change is made, the type of change, and whether the change affects a medication you are currently using.

(1)  Formulary changes made year-to-year

Every year your Medicare Part D (or Medicare Advantage plan) will send you an Annual Notice of Change (ANOC) letter in late-September or early-October summarizing upcoming changes to your plan coverage for the next year - for example, you may see plan premiums change or changes in your copays.  Your Medicare drug plan will also send you next-year's comprehensive formulary or provide a link where you can download next-year's formulary.  However, the plan will not specifically provide you notice of changes in the coverage of your specific medication.  Instead, you will need to review the plan's comprehensive formulary to see how your drug coverage may change next year.

If you review the plan's comprehensive formulary and see that one or more of your medications is not covered next year, you can use the annual Open Enrollment Period to change Medicare drug plans to ensure the most complete and affordable coverage.

But, if during the annual Open Enrollment Period (ending December 7), you don't notice that your drug(s) are no longer covered by your drug plan next year, you still have some options.

If, in January, you find that your medication is no longer covered by your new plan  you will have the right during the first 90 days of your new plan coverage to ask your Medicare prescription drug plan for a one-time, transition fill (a temporary 30-day supply of a medication you already have been using).  To initiate a transition fill request, call the Member Services telephone number found on your Member ID card or your plan’s printed information.  You can click here to read more about transition fills.

(2)  Formulary changes made during the first 60-days of the plan year

In general, your Medicare Part D plan is not permitted to change the plan's formulary or drug list during the first 60 days of the new year.  However, the exceptions to this rule are "when the FDA deems a Part D drug unsafe or a manufacturer removes a Part D drug from the market" - in such cases, the drug can be removed from the comprehensive formulary even before the start of the new plan year.

(3)  Formulary changes made after the first 60-days of the plan year

After the first two months of coverage, your Medicare Part D plan is permitted to change the plan's formulary or drug list throughout the remainder of the year.  And, in general, your Medicare Part D plan must either provide you with a 30-day advance written notice of any changes to your formulary that might affect you or provide you with a 1-month supply of your medication after you learn of the formulary change.

However, a Medicare Part D plan can remove a medication from the plan's formulary without prior notice in several situations:

• A brand-name medication is being dropped from the formulary because a new generic drug has become available and will provide more affordable coverage to plan members (alternatively, the plan can keep the brand-name drug on the formulary, but change the cost or coverage rules for the brand-name drug when a new generic is added).
• The FDA finds a drug unsafe or the drug manufacturer has removed the drug from the market place.
  

In these two cases, your Medicare Part D plan will then notify you after the drug's formulary removal.

In practice, most Medicare Part D plans make every effort to ensure that you are aware of any formulary changes that will affect you and will send you a written notice of any drug list changes in your Explanation of Benefits (or EOB) letter, plan newsletter, or a special mailing - and your Medicare Part D plan’s website will be regularly updated with information about formulary changes online.

You can read more about what to do if you receive a drug drop notification from your plan provider in our FAQ:
Will my Medicare Prescription Drug Plan need to notify me if its list of covered drugs (formulary) changes?


If you have a question about formulary changes, that we missed, click here and to let us know

Please note: The 60 day notice requirement for formulary changes was changed in 2018 to a 30 day advance notice.

Chapter 6 "Part D Drugs and Formulary Requirements" in the 2016 Medicare Prescription Drug Benefit Manual (online 05/22/2024) notes that the formulary change notice requirement is 60 days or providing a 60 day transition supply for certain changes to a Medicare plan's formulary - and even in 2024, some Medicare drug plans still provide their Medicare plan members with 60 days notice of formulary changes.

However, as of 2018, a Medicare Part D drug plan is only required to provide a minimum of a 30 day advance notice of formulary changes - as was established in the April 2018 Final Rule, where the Centers for Medicare and Medicaid Services updated the federal regulations by lowering the notice requirement to 30 days or a 1-month supply (for certain formulary changes), noting in the Final Rule comments:

With our proposed revisions, the regulation establishes different notice requirements for three types of midyear changes: (i) Substitutions of newer generics that meet the requirements of § 423.120(b)(5)(iv) as proposed; (ii) drugs removed from formularies on the basis that they are deemed unsafe by the FDA or withdrawn by their manufacturer consistent with current § 423.120(b)(5)(iii); and (iii) all other midyear formulary changes that do not fall into one of the first two types, which are governed by § 423.120(b)(5)(i) and, as finalized, would require 30 days advance notice to affected enrollees (as defined in § 423.100) and, as applicable, an approved month's fill for affected enrollees (as defined in § 423.100).

While the changes we are finalizing to § 423.120(b)(5) reduce the number of days' direct advance notice required for other midyear formulary changes from 60 to 30 days, they do not otherwise change requirements or guidance applicable to these other midyear formulary changes. Thus, consistent with the changes we are finalizing in this rule, Part D sponsors are required, for example, to provide current and prospective Part D enrollees with at least 30 days' prior notice on their websites of other midyear formulary changes (§ 423.128(d)(2)(iii)). [emphasis added]

See:
https://www.federalregister.gov/documents/2018/04/16/ 2018-07179/medicare-program-contract-year-2019-  policy-and-technical-changes-to-the-medicare-advantage-medicare