The CAR-T Reimbursement Gap: A 2026 Benchmark Analysis

Three gaps that don't appear in standard revenue cycle reports.

The therapy works. The hospital loses money on every case. The DRG pays $314,231. The drug costs approximately $530,000. Total care per case runs $608,100 at the median, and 8.5% of cases exceed $1 million. Outlier payments close part of the gap on 66% of cases, but three structural features of the outlier mechanism guarantee they never close it entirely. In Medicare Advantage, the problem compounds: denial rates for high-cost therapies run systemically higher than traditional Medicare, and 65 health systems have exited MA plans across 2024 and 2025 combined. The third gap is the asymmetry between what payers model before they negotiate and what most programs know when they sit down.

The per-case gap: what CMS pays vs. what CAR-T actually costs.

MS-DRG 018 covers every inpatient CAR-T case under the Medicare Inpatient Prospective Payment System. The FY2026 base rate, effective October 1, 2025, is $314,231, a 16.8% increase over the FY2025 rate of $269,139, the largest single-year jump since the DRG was created. The median wholesale acquisition cost across all seven FDA-approved CAR-T products is approximately $530,000, before the infusion suite, the ICU, or the 100-day follow-up.

The clinical trial adjustment factor deserves specific attention: CMS cut it from 0.33 to 0.16 for FY2026, a 43% reduction. The effective clinical trial payment drops to $50,277. For a drug that costs approximately $500,000, that is not a reimbursement challenge; it is an operating crisis for programs treating trial-enrolled patients.

Drug acquisition cost across all seven approved products ranges from $462,000 (Tecartus) to $593,533 (Kymriah), with a median around $530,000. Every approved product exceeds the FY2026 base rate before a single bed-day is counted. Total cost of care, which adds conditioning chemotherapy, inpatient management, CRS and neurotoxicity management, and follow-up, runs to a published median of $608,100 (Di et al., JNCI Cancer Spectrum, Aug 2024), with 8.5% of cases exceeding $1 million.

1. The 20% haircut. Medicare pays 80 cents on the dollar for all excess costs above the fixed-loss threshold. The remaining 20% is unrecoverable by design.
2. Charge compression via cost-to-charge ratio. Drug charges are converted to costs using the hospital's pharmacy CCR, typically 0.25 to 0.35, which systematically understates actual drug acquisition costs for high-WAC products.
3. The threshold floor. The first $40,397 of excess costs above the DRG base rate receives no outlier reimbursement at all.

Published per-case loss estimates, even after outlier payments, range from $63,000 to $304,000 at academic medical centers (Penn Center for Cancer Care Innovation / JCO, 2020). A separate survey of 92 FACT/REMS-certified centers found that drug acquisition cost alone exceeded the full DRG payment by a median of $186,500 (Leech, Cohen, Jagasia et al., The Oncologist, 2020), with financial viability reported as the top barrier to CAR-T program administration.

The Medicare Advantage denial problem.

Medicare Advantage enrolled 33.6 million beneficiaries in 2024, 54% of all eligible Medicare recipients. For oncology programs, this means over half of patients walking through the door are on MA plans, where prior-authorization denial dynamics for high-cost therapies differ structurally from traditional Medicare.

A 2022 HHS Office of Inspector General review (OEI-09-18-00260) of the 15 largest MA organizations found that 13% of prior-authorization denials met Medicare's own coverage rules, and every one of those denials, when appealed, was reversed. OIG's 2026 MA Compliance Program Guidance cites that report and flags AI-driven prior authorization as an emerging enforcement risk.

The 80.7% appeal-overturn rate is the number that matters most: the vast majority of denied MA prior authorizations, when challenged, are ultimately approved. But only 11.5% of denials are ever appealed, meaning approximately 3.6 million denials per year go unchallenged despite an expected 80%+ overturn rate. UnitedHealthcare carried the highest denial rate among major MA insurers at 12.8% in 2024; Humana was lowest at 5.8%.

MedPAC's March 2025 Report to Congress documented a 20% cost premium for MA enrollees over equivalent fee-for-service beneficiaries, approximately $84 billion annually, attributed to coding intensity and favorable selection. The most direct evidence of the resulting strain is behavioral: 32 health systems exited MA plans in 2024 and 33 more in 2025, including Mayo Clinic, Mass General Brigham, and Mount Sinai, citing prior-authorization burden and reimbursement inadequacy.

CMS does not publicly report MA prior-authorization data broken out by service type, so a CAR-T-specific MA denial rate does not exist in published form. What the research does show: a University of Nebraska Medical Center analysis found private/MA-insured CAR-T patients experienced a median 37-day delay to apheresis versus 17 days for publicly insured patients, a 20-day difference (P=.0005) that is clinically significant for a population that has already failed two or more prior lines of therapy.

The contract intelligence gap.

The per-case gap and MA denial dynamics are structural features of the reimbursement environment; they exist whether or not a program negotiates aggressively. The contract intelligence gap is different: it is solvable, and only with better information. Payers model CAR-T costs before any negotiation happens. Most cancer center programs launch without negotiated single case agreements (SCAs), without Revenue Code 891 billing protocols built into charge capture, and without a payer-by-payer analysis of where the outlier threshold sits relative to expected costs.

A single-center University of Nebraska Medical Center study (n=65) found that 68% of CAR-T patients required an SCA, and that SCA negotiation added a median of 24 days to the path to treatment (P<.0001): brain-to-vein time was 17 days without an SCA versus 33 days with one required. A separate ASH 2023 analysis found 66% of private/MA-insured patients required an SCA. No multi-center benchmark exists for what programs are actually negotiating versus standard contract rates; commercial rates remain proprietary.

Revenue Code 0891 is the designated code for reporting CAR-T drug costs on institutional claims, paired with product-specific HCPCS Q-codes (Revenue Code 0892 is for gene therapy). CPT codes 38225 through 38228 replaced the prior Category III codes effective January 1, 2025, and a December 2025 CMS billing instruction (MM14247) clarified three MS-DRG 018 payment-adjustment scenarios that billing teams need to identify before a claim leaves the building. Inpatient CAR-T drug costs are bundled into the MS-DRG 018 payment; outpatient administration is paid separately at ASP+6%, subject to the 72-hour rule, a distinction that matters for programs exploring outpatient administration.

All seven FDA-approved CAR-T products require prior authorization from every major commercial payer. Anthem/Elevance's site-of-service requirement, Center of Medical Excellence designation with community-only offices explicitly excluded, is the most restrictive among major payers. No major commercial payer has publicly documented outcomes-based agreement structures for CAR-T as of this report; where they exist, they are negotiated confidentially between manufacturers and individual payers.