Usually 90 days. Your 30-day supply transition fill is usually only available during the first 90 days of your new Medicare drug plan coverage.

If you are living in a long-term care (LTC) facility, then you are granted at least a 91-day supply transition fill and your Medicare plan may extend the availability of the transition fill over a longer period. You can read more in our FAQ about transition fills in a LTC facility.

And as reference:

As noted by the Centers for Medicare and Medicaid Services (CMS) in the Medicare Prescription Drug Benefit Manual, Chapter 6 – Part D Drugs and Formulary Requirements, Section 30.4 - Transition, (Rev. 18, Issued: 01-15-16, Effective: 01-15-16; Implementation: 01-15-16):

30.4.4 - Transition Timeframes and Transition Supply

Within the first 90 days of coverage under a new plan, plans must provide a transition supply when the beneficiary requests a non-formulary drug. This 90 day timeframe applies to retail, home infusion, long-term care, and mail-order pharmacies. CMS believes it makes sense to both limit and define the amount of time during which a transition process is applicable. Thus, plans are required to provide a temporary fill anytime during the first 90 days of a beneficiary’s enrollment in a plan. However, since certain enrollees may join a plan at any time during the year, this requirement applies beginning on such an enrollee’s first effective date of coverage instead of to the first 90 days of the plan year. If an enrollee leaves a plan and re-enrolls during the original 90 day transition period, the transition period begins again with the new effective date of enrollment, because it is possible that the enrollee’s drug therapy changed while the enrollee was not with the plan and that therapy could be potentially interrupted. However, if there is no gap in coverage, there is no new transition period.

Section 30.4.4.1 - Timeframe and Transition Supply in the Retail Setting

"In the retail setting, the transition fill of non-formulary Part D drugs must be for at least 30 days, unless the prescription is written by a prescriber for less than 30 days. Part D sponsors must allow multiple fills to provide at least 30 days of medication in accordance with 42 CFR §423.120(b)(3)(iii)(A). If the smallest available marketed package size exceeds a 30 day supply, the sponsor must still provide a transition supply when required. Part D sponsors and their processors must determine how to process claims in such cases."

Section 30.4.4.2 - Timeframe and Transition Supply in the Long Term Care Setting

"The transition supply of non-formulary Part D drugs for a new enrollee in an LTC facility must be for at least 91 days, and may be up to at least 98 days to be consistent with the applicable dispensing increment in the LTC setting (unless a lesser amount is actually prescribed by the prescriber). Part D sponsors must allow multiple fills if needed to provide the full amount of medication prescribed, in accordance with 42 CFR §423.120(b)(3)(iii)(B). If the smallest available marketed package sizes do not align with this timeframe, the sponsor must still provide a transition supply when required. Part D sponsors and their processors must determine how to process claims in such cases. CMS is requiring up to a 91- to 98-day transition supply given that many LTC pharmacies and facilities must dispense brand name medications in 14-day or less increments. Also, sponsors must honor multiple fills of non-formulary Part D drugs as necessary during the entire length of the transition period.

CMS is permitting Part D sponsors the option of sending required transition fill notices to network long term care pharmacies. In sending enrollees residing in LTC facilities a model transition notice via U.S. mail within 3 business days of adjudication of the transition fill, Part D sponsors may instead elect to send the beneficiary transition notice to the LTC pharmacy serving the beneficiary’s LTC facility. The LTC pharmacy must then ensure delivery of the notice to the beneficiary within 3 business days of adjudication of the fill.

Part D sponsors electing this option must update their existing transition policy to specifically address that:

1. The sponsor maintains documentation of the LTC pharmacies’ willingness to be delegated transition notice responsibilities; and

2. The sponsor maintains a fully functional electronic communication process with the LTC pharmacy once a transition fill has occurred (within 3 business days).

3. The LTC pharmacy will maintain a process that demonstrates notice has been provided to the beneficiary (or his/her representative) within the 3-day period.

This option must be in place prior to the start of the contract year; otherwise, the Part D sponsor must continue to provide notice directly to the beneficiary (or his/her designated representative) via U.S. mail."