The prior notification of a mid-year formulary change will depend on the type of formulary change.

(1) No advance notice of a formulary change when replacing your brand-name drug with a new generic.

Your Medicare drug plan (stand-alone Medicare Part D plan or Medicare Advantage plan that includes drug coverage) is not required to notify you before dropping coverage for your brand-name drug when a new generic equivalent is introduced.  You may notice in your Medicare plan's Evidence of Coverage (EOC) document that your plan notes:

"[Your Medicare plan] may immediately remove a brand name drug on our Drug List if [the plan is] replacing [the brand drug] with a new generic drug that will appear on the same or lower cost sharing tier and with the same or fewer restrictions."

"Also, when adding the new generic drug, [your Medicare plan] may decide to keep the brand name drug on our Drug List, but immediately move it to a different cost-sharing tier or add new restrictions [when a new generic equivalent is introduced].  [Your Medicare plan] may not tell you in advance before we make that change—even if you are currently taking the brand name drug"

(2) No prior notice of a formulary change is required when a formulary drug is removed because the FDA withdraws the drug from the market.

"Once in a while, a drug may be suddenly withdrawn because it has been found to be unsafe or removed from the market for another reason. If this happens, we will immediately remove the drug from the Drug List. If you are taking that drug, we will let you know of this change right away." [emphasis added]

(3) You will receive a 30-day notice for most other formulary changes (or a 30-day supply of the affected formulary drug).

In general, your Medicare Part D plan will give you a 30-day notice if there is any other type of coverage change for any medications that you have taken during the plan year (January through December).   Alternatively, your Medicare drug plan will provide you with a 1-month supply of the impacted formulary drug.  For example, if you are using a brand-name drug that is being replaced by an existing generic, your Medicare Part D plan will notify you in advance of the formulary change - or provide you with a 1-month supply of the medication.

As reference, Medicare provides Medicare drug plans with the following "model" language to be used in the plan's documentation:

"During the year, following Medicare rules, we may make changes to our Drug List. We may add new drugs, remove drugs, and add or remove restrictions on coverage for drugs. We are also allowed to change drugs from one cost-sharing tier to another.

-- Some changes to the Drug List may happen immediately:
We may immediately replace a brand-name drug with a new generic that will appear on the same or lower cost-sharing tier and with the same or lower restrictions. Or we may immediately add the new generic and add new restrictions to the brand-name drug or move it to a different cost-sharing tier or both.

-- For all other changes to drugs you take, you will have at least 30 days’ notice before any changes take effect. "  [formatting added]

Question:  Where can I see my Medicare plan's formulary changes that directly impact me?

Check your monthly EOB letter and other plan correspondence.
You will notice formulary changes in Section 4 of your Medicare Part D plan's Explanation of Benefits (EOB) letter that you receive every month.  Formulary changes on your EOB can include the addition of new drugs, the removal of drugs from the formulary, adding or removing usage management restrictions on coverage for drugs, and moving a drug from one cost-sharing tier to another.  Read more and see examples of change in EOB Section 4: Updates to the plan's Drug List that will affect drugs you take.

Please also pay attention to any letters you receive from your Medicare drug plan (or electronic correspondence if you are using a "paperless" option) and look for any notice that one of your Medicare Part D drugs is being replaced or dropped from your formulary because of the addition of another medication.

Question:  Where can I see my Medicare plan's formulary changes that do not directly impact me?

Check your plan's website.
If you are not currently receiving coverage for a particular formulary medication, you probably will not know about future formulary changes (for example, that the drug will be dropped from the formulary) - and even if you search your Medicare plan’s online formulary or the Medicare.gov site, you will not see an indication that a plan’s formulary is about to change.  However, your Medicare plan's website should show any current formulary changes.

Remember:  Unless noted otherwise, you will have at least 30 days notice before any changes take effect unless a serious safety issue is involved (for example, a drug is taken off the market for safety reasons) or replaced with a newly-introduced generic drug.

Question:  What can I do if I don't want to use the new generic or alternative drug, but instead want to continue using my brand-name drug?

You have the right to challenge the formulary change by requesting a Formulary Exception (a type of Coverage Determination), whereby you ask your plan to cover a non-formulary drug or change how your formulary drug is covered. You can contact your plan (using the toll-free telephone number found on your Member ID card) and ask a plan representative how to proceed with a Formulary Exception request - or telephone a Medicare representative at 1-800-633-4227 (1-800-Medicare) for assistance.

Please also see:

» Requesting a Coverage Determination or Formulary Exception

» Prescribing Physician’s Role in Coverage Determination Processes

For more about mid-year formulary changes, please see:

Federal regulations: 42 CFR §423.120(b)(5) "Provision of notice regarding formulary changes"