For a hospital CFO looking at 340B in the 2027 budget, the number that matters is $100 billion. That is roughly what the 340B Drug Pricing Program moved in 2025, nearly double the $53.7 billion it moved in 2022. Two separate policy moves converging on January 1, 2027, are about to reshape that number, and CFOs at 340B-participating systems have roughly one quarter left to model both before either lands on the P&L.

The first move is a pilot. HRSA on July 31, 2026, authorized the revised 340B Rebate Model Pilot Program, letting qualifying manufacturers, if they choose, deliver the 340B ceiling price through post-dispense claim rebates rather than at the point of purchase. Manufacturers had to submit rebate plans by August 24, 2026, to be in the initial cohort; approved plans take effect January 1, 2027. Which specific drugs sit in the revised pilot depends on which manufacturers submitted qualifying plans — the July 2026 announcement itself does not publish the drug list. What we do know from the earlier iteration authorized in late 2025 is what the model looks like operationally: ten drugs matching the Inflation Reduction Act’s initial negotiated-price set, with providers paying wholesale acquisition cost (WAC) at the point of dispense, filing rebate claims through the third-party Beacon platform within 45 days, and expecting rebate payment within 10 days of claim validation.

The second move is a proposed Medicare payment cut. CMS’s proposed 2027 Hospital Outpatient PPS rule would reduce Medicare reimbursement for 340B-acquired drugs from ASP plus 6% to ASP minus 33.4% — a 37% reduction. CMS is required to maintain budget neutrality across the OPPS, so the money does not leave the program: CMS proposes to raise non-drug OPPS payment rates by 8.44% across the board to absorb the offset. KFF, drawing on CMS’s own impact scoring, puts the net Medicare-spending swing at roughly $4.85 billion in 2027 in each direction. If the rule is finalized as proposed, it takes effect January 1, 2027.

The finance question is not whether these moves happen. HRSA’s pilot is authorized. The OPPS rule is proposed and procedurally defensible in a way its 2018 predecessor was not — CMS completed the cost acquisition survey the Supreme Court’s 2022 decision faulted the earlier rule for lacking. The question is: what does your P&L look like on the other side?

On the rebate side, the cash-flow question is the operating question. A 340B-participating provider dispenses a covered drug, pays WAC upfront to acquire it, submits a claim through Beacon within 45 days, and then waits for manufacturer validation before the rebate arrives. The 10-day rebate-payment expectation begins after validation, and the pilot documentation does not lock down how long validation itself is allowed to take. Best case, working-capital drag is a few weeks. Worst case is whatever the validation window turns out to be in practice. On roughly ten drugs across more than 42,000 covered entities and more than 32,000 contract pharmacy locations, even a well-behaved rebate pipeline creates cash lag that did not previously exist. For a CFO of a system with significant Eliquis or Enbrel volumes — both among the highest-revenue drugs on the earlier list — the answer to “what is the WAC-to-rebate lag on our 340B book” is now a real number worth calculating rather than a rounding error worth assuming.

On the OPPS side, the revenue impact is starkly segmented. KFF’s analysis of the proposed rule finds the redistribution running most strongly against safety-net hospitals — the same class the program was originally designed to support — and most strongly toward for-profit hospitals, which cannot participate in 340B in the first place. Safety-net hospitals in aggregate would see a net OPPS revenue reduction of roughly 5.8% under the proposal. For-profit hospitals in aggregate would see a net OPPS revenue increase of roughly 7.4%. In between: major teaching hospitals see about a 4.3% net reduction; large urban hospitals (500 beds or more), about 5.2%; government hospitals, about 3.0%; and nonprofit hospitals overall, about 0.5%. Small urban hospitals and non-teaching hospitals come out modestly ahead; rural sole community hospitals, which are exempt from the 340B cut but participate in the offsetting non-drug uplift, gain roughly 5.7%.

Children’s hospitals and PPS-exempt cancer hospitals are also exempt. Critical access hospitals sit outside the rule entirely because they are not reimbursed under OPPS to begin with.

The class most exposed by CMS’s own scoring is the DSH-heavy, urban, safety-net teaching hospital. That is a class already operating at margin percentages a for-profit CFO would consider unsustainable, and KFF notes the same class carries elevated exposure to the 2025 reconciliation law’s Medicaid reductions. Two of the largest revenue mechanisms these systems rely on are moving in the same direction at the same time.

None of this is a call to panic. It is a call to model. What The Margin recommends CFOs work through this quarter:

1. Model the rebate cash-flow lag on your specific 340B drug book, not on an abstract ten-drug list. How much working-capital drag the rebate model creates depends on your dispensing volumes of the specific drugs in the revised pilot. If they represent 3% of your 340B revenue, the lag is a treasury nuisance. If they represent 30%, it changes how you manage cash across the year.
2. Reforecast 2027 OPPS revenue under the ASP-minus-33.4% scenario, with the 8.44% non-drug uplift, at the service-line level. A system that is drug-heavy in outpatient oncology and light in interventional volumes lands very differently from one that is drug-light and heavy on non-drug procedures. The aggregate class-average figures obscure that variance; your service-line mix determines whether you are a “-5.8% safety-net hospital” or something meaningfully different.
3. Build the board narrative now, not in Q4. The 340B story is politically charged and easy to distort in either direction. A CFO who walks into the board meeting with the specific dollar impact, the cash-flow question, and the exposure to the rebate pilot — quantified against the system’s own book — controls the conversation. A CFO who cannot ends up defending against media graphs.
4. Model the litigation scenario. The rebate model has already been enjoined once in an earlier form. The OPPS 340B cut has litigation history reaching back to 2018. Neither of these is a finished story. Build 2027 forecasts with a “rule finalized as proposed” case and a “rule enjoined or narrowed” case, and know what each looks like before the board asks.

The 340B line is no longer a discount running quietly in the background. In 2027 it becomes a first-order finance question that either you have modeled or your board is about to ask why not.