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Change Tracker · updated at each CMS milestone
On January 27, 2026, CMS selected drugs for the third negotiation cycle — the first to reach physician-administered drugs. Five of the fifteen are majority-Part B, and they sit squarely in rheumatology, GI, neurology, and allergy buy-and-bill. From January 1, 2028 their payment limits become 106% of the negotiated Maximum Fair Price instead of ASP+6%. This page tracks the five drugs, the dates, the settled math — and the one question CMS has explicitly left open.
Settled: the payment limit becomes 106% of MFP, published prospectively in the same quarterly file this site tracks. Unsettled: how practices acquireat MFP — buy at the negotiated price up front, or buy high and chase a refund. CMS has deferred Part B effectuation to “future policymaking,” and that deferral is the entire ballgame for buy-and-bill cash flow.
CMS naming and spend; current payment limits from the Q3 2026 file (effective July 1, 2026).
| Drug | HCPCS | Manufacturer | Specialty | Spend | Limit / unit | Benefit split |
|---|---|---|---|---|---|---|
| Orencia (abatacept) | J0129 | Bristol Myers Squibb | Rheumatology | $2.45B | $45.86 / 10 mg | IV abatacept (J0129) is Part B; self-injected subcutaneous Orencia flows to Part D. The highest-spend Part B selection. |
| Entyvio (vedolizumab) | J3380 | Takeda | Gastroenterology | $1.48B | $21.62 / 1 mg | IV vedolizumab (J3380) is Part B; Entyvio Pen (subcutaneous) typically flows to Part D. No biosimilar. |
| Botox; Botox Cosmetic (onabotulinumtoxinA) | J0585 | AbbVie | Neurology / urology / PM&R | $1.14B | $6.51 / 1 unit | One code covers both products — CMS selected the manufacturer's naming; including the cosmetic product changes no Medicare coverage. |
| Xolair (omalizumab) | J2357 | Genentech | Allergy / pulmonology | $1.08B | $46.59 / 5 mg | Office-administered omalizumab is Part B; self-administration shifts it to Part D. Also on Aetna's CBM pharmacy-migration list — channel and price pressure on the same drug. |
| Cimzia (certolizumab pegol) | J0717 | UCB | Rheumatology / GI | $0.79B | $3.44 / 1 mg | J0717 carries the direct-supervision note — physician-administered only; self-injected Cimzia is Part D. |
The table nobody publishes: today’s add-on dollars per typical maintenance dose, and what they become if the MFP lands 25%, 40%, or 60% below current ASP.
The arithmetic is strictly proportional: the add-on is 6% of the price basis, so whatever the MFP cuts from the price, it cuts from the add-on. Avalere’s 2022 model of likely Part B selections averaged a 47.2% add-on reduction(33.8% in rheumatology); Milliman’s 2026 worked example used a 60% cut. The MFPs themselves are unknown until November 30, 2026 — these columns are scenarios on public CMS data, not predictions.
| Drug | Typical dose | Allowable / dose | Add-on / dose today | MFP −25% | MFP −40% | MFP −60% |
|---|---|---|---|---|---|---|
| Orencia | 750 mg IV maintenance (60–100 kg), q4w | $3,439 | $195 | $146 | $117 | $78 |
| Entyvio | 300 mg IV maintenance, q8w | $6,487 | $367 | $275 | $220 | $147 |
| Botox | 155 units, chronic-migraine protocol, q12w | $1,008 | $57 | $43 | $34 | $23 |
| Xolair | 300 mg (illustrative; label dosing is IgE/weight-tiered), q4w | $2,795 | $158 | $119 | $95 | $63 |
| Cimzia | 400 mg maintenance, q4w | $1,378 | $78 | $58 | $47 | $31 |
Add-on figures are the 6/106 share of the allowable, before sequestration; after the 2% sequester on Medicare’s 80% share, collected add-on runs ≈4.3% of the price basis. Doses are label maintenance doses for a typical adult; your case mix varies. And the allowable itself falls with MFP too — at −60%, a $3,439 Orencia administration reimburses about $1,376 all-in.
The IRA amended SSA §1847A so that for a selected drug during its price-applicability period the limit is “106 percent of the maximum fair price” (42 U.S.C. §1395w-3a(b)(1)(B)). And it lands prospectively: the CY 2026 Physician Fee Schedule final rule states that “for quarters in which Medicare payment is based on MFP, the Medicare Part B Drug Payment Limit File will display the MFP-based payment limit.” CMS will suspend ASP publication for negotiated Part B drugs until generic or biosimilar entry. The same quarterly file this site’s leaderboard tracks will simply print the new number.
The IPAY 2028 final guidance, responding directly to Part B effectuation comments: CMS “will address manufacturer effectuation of the MFP for selected drugs or biological products payable under Part B in future policymaking.” The generic framework gives manufacturers two routes — prospective (the acquiring entity pays no more than MFP) or retrospective (a refund of the difference, within a 14-day prompt-payment window through the Medicare Transaction Facilitator). For a practice carrying five-figure-per-dose inventory, those two routes are very different businesses: one is a price, the other is a receivable. COA’s warning to CMS calls the unresolved Part B effectuation process potentially “a practice-ending event for many community oncology practices.” This page updates the moment CMS answers.
| Date | Milestone | Detail |
|---|---|---|
| ✓ Jan 27, 2026 | Selected-drug list published | CMS names the 15 IPAY-2028 drugs — the first negotiation cycle to reach Part B. Five are majority-Part B. |
| ✓ Feb 28, 2026 | Manufacturer agreements | All 15 manufacturers signed participation agreements (CMS announcement, Mar 13, 2026). |
| ✓ Jun 1, 2026 | Initial CMS offers | CMS sends opening Maximum Fair Price offers; the negotiation period runs to Nov 1, 2026. |
| Nov 30, 2026 | MFPs published | CMS's deadline to publish the agreed Maximum Fair Prices — the number that prices every scenario below. |
| Mar 1, 2027 | MFP explanations | CMS publishes its explanation of each negotiated price. |
| Jan 1, 2028 | MFP-based limits effective | The Part B payment limit for each selected drug becomes 106% of MFP, replacing ASP+6%. |
Five of the 15 selected drugs have the majority of their spending under Part B: Orencia (abatacept, J0129), Entyvio (vedolizumab, J3380), Botox (onabotulinumtoxinA, J0585), Xolair (omalizumab, J2357), and Cimzia (certolizumab pegol, J0717). Cosentyx is Part D-majority with notable Part B use. The other selections — Trulicity, Biktarvy, Erleada, Kisqali, Verzenio, Lenvima, Rexulti, Xeljanz, Anoro Ellipta — are Part D drugs.
By statute (SSA §1847A(b)(1)(B), added by the IRA), the payment limit for a selected drug during its price-applicability period is 106% of the Maximum Fair Price — replacing 106% of ASP. CMS confirmed in the CY 2026 Physician Fee Schedule final rule that the quarterly Part B payment limit file will simply display the MFP-based limit. After the 2% sequester on Medicare's 80% share, the effective add-on is roughly 4.3% of MFP.
The reimbursement side is prospective and settled: the MFP-based limit appears in the quarterly payment limit file. The acquisition side is genuinely unresolved — CMS's IPAY 2028 final guidance says it 'will address manufacturer effectuation of the MFP for selected drugs or biological products payable under Part B in future policymaking.' The generic framework allows manufacturers to provide MFP access either prospectively (acquisition price at or below MFP) or retrospectively (a refund of the difference within a 14-day prompt-payment window). Whether buy-and-bill practices buy at MFP up front or buy high and chase refunds is the open question.
No. The statute limited the first two cycles (10 drugs effective 2026, 15 effective 2027) to Part D drugs; Part B drugs became negotiation-eligible starting with initial price applicability year 2028. IPAY 2028 is the first cycle to reach physician-administered drugs.
No. The statute sets 106% of MFP with no transition, and a full-text search of the 381-page IPAY 2028 final guidance finds no add-on or hold-harmless provision. Pending legislation (S.2764 / H.R. 5391, the Protecting Patient Access to Cancer and Complex Therapies Act) would keep practice reimbursement at ASP+6% and have manufacturers rebate the difference to CMS — but it is not law. Don't confuse the IRA's temporary ASP+8% add-on for qualifying biosimilars, which does not apply to selected drugs.
CMS must publish the agreed MFPs by November 30, 2026, with its explanation of each price by March 1, 2027. Prices take effect January 1, 2028. Until publication, any specific MFP figure is speculation — the scenarios on this page are arithmetic on public data, not predictions.
Price history for the watchlist drugs: the drug trend pages chart every quarterly payment limit back to 2005. How this data is built and corrected: the Data Desk.
carecostoptimizer.com/resources/margin-watch/ira-part-b-2028-watchlist. Verified June 10, 2026. Free to cite with attribution. General information, not billing, legal, or financial advice.The practice X-Ray prices your exposure drug by drug — how much of your margin rides on codes facing MFP, biosimilar entry, or payer sourcing pressure — against your actual mix and payer book.