On November 9, 2026, the Centers for Medicare & Medicaid Services published final rule CMS-4215-F in the Federal Register (91 FR 72176, document 2026-22792, RIN 0938-AV90), codifying the Medicare Drug Price Negotiation Program at 42 CFR part 429 and amending the Medicare Prescription Drug Benefit Program at 42 CFR part 423. The regulations are effective on December 5, 2026. They apply to the Negotiation Program beginning with initial price applicability year 2029, and to Part D coverage beginning January 1, 2029.
Primary manufacturers of Medicare Part B and Part D single-source drugs that can be selected for initial price applicability year 2029, NDA and BLA holders of fixed-combination products CMS treats as new formulations of an existing drug, manufacturers of drugs that formerly qualified for the orphan-drug exclusion, and Part D plan sponsors that must cover selected drugs at a negotiated price no higher than the maximum fair price must map each Part B and Part D product, including fixed-combination drugs and former orphan drugs, against the codified 42 CFR part 429 rules before they take effect, and have Part D coverage reflect the negotiated price, by December 5, 2026, or a product CMS groups as one qualifying single-source drug can be selected and bound to a maximum fair price from initial price applicability year 2029, and a Part D plan that pays above that price for a selected drug is outside the negotiated-price rule in Social Security Act section 1860D-2.
What does CMS-4215-F put into 42 CFR part 429?
CMS-4215-F replaces proposed rule CMS-4215-P of June 16, 2026 (91 FR 36236) with a final codification of the Negotiation Program for initial price applicability year 2029. The maximum fair price is the price negotiated for a selected drug under the Medicare Drug Price Negotiation Program, Social Security Act sections 1191 through 1198.
The table of contents places qualifying single source drugs at section 429.125. Fixed-combination drugs sit under section 429.125(b). Time since approval or licensure is the heading at section 429.125(c). The orphan-drug exclusion is the heading at section 429.125(e)(1), beside the low-spend exclusion at section 429.125(e)(2) and the plasma-derived product exclusion at section 429.125(e)(3). Bona fide marketing and deselection are the headings at sections 429.125(d), 429.130 and 429.135. The definitions list includes Temporary Floor for Small Biotech Drugs. The rule also amends 42 CFR part 423.
Who must map products before the rules take effect?
Primary manufacturers of Part B and Part D single-source drugs eligible for initial price applicability year 2029 map products to part 429. NDA and BLA holders of fixed-combination products CMS treats as new formulations map them under section 429.125(b). Manufacturers of drugs that formerly qualified for the orphan-drug exclusion map them against section 429.125(e)(1). Part D plan sponsors align coverage with the part 423 amendments. Obsidian's record of the Medicare Drug Price Negotiation Program holds 5 dated milestones ahead, the next on November 30, 2026.
Social Security Act sections 1191 through 1198, added by Pub. L. 117-169 and adjusted by section 71203 of Pub. L. 119-21 (July 4, 2025), remain the statute. CMS-4215-F is the codification that starts with initial price applicability year 2029.
What must be finished by December 5, 2026?
December 5, 2026 is the effective date of CMS-4215-F. Initial price applicability year 2029 maximum fair prices, up to 20 Part B and Part D drugs, apply from January 1, 2029, the same day Part D coverage applicability starts. Map each product to the final rule, not to CMS-4215-P: fixed combinations, time since approval, the orphan-drug exclusion, bona fide marketing, the small-biotech floor heading, and the part 423 amendments.
| Date | What is fixed |
|---|---|
| June 16, 2026 | Proposed rule CMS-4215-P, 91 FR 36236 |
| November 9, 2026 | Publication of CMS-4215-F, 91 FR 72176, document 2026-22792 |
| December 5, 2026 | Effective date of 42 CFR part 429 and the part 423 amendments |
| January 1, 2029 | Part D coverage applicability, and application of IPAY 2029 maximum fair prices (up to 20 Part B and Part D drugs) |
A separate CMS deadline, November 30, 2026, is the date to publish negotiated or renegotiated maximum fair prices for the initial price applicability year 2028 cycle. CMS-4215-F does not publish those prices. See the printed rule.
What happens if a product is grouped or a plan pays above the maximum fair price?
A product CMS groups as one qualifying single-source drug can be selected and bound to a maximum fair price from initial price applicability year 2029. A Part D plan that pays above that price for a selected drug is outside Social Security Act section 1860D-2. Continuous per-jurisdiction monitoring from Obsidian surfaces a Federal Register final rule of this kind on publication.
Before December 5, 2026, check which NDAs and BLAs sit under section 429.125(b), which products sit under section 429.125(e)(1), and whether Part D coverage reflects the negotiated price. Keep the November 30, 2026 IPAY 2028 price publication as a separate act.
