A watchdog referral program has trimmed $78 million from what Medicare and its enrollees pay for Part B drugs since 2013, according to a September 2026 data brief from the Department of Health and Human Services Office of Inspector General. Patients generally owe 20 percent of the Medicare-approved amount on those drugs after the Part B deductible, so a lower payment ceiling reaches the patient’s side of the bill as well as the government’s. The brief does not say how the $78 million divides between the two.
A 5 percent gap between two price reports starts the referral
The mechanism rests on two prices that drugmakers report. Each quarter, OIG compares the average sales price manufacturers report for a Part B drug with the average manufacturer price reported through the Medicaid drug rebate program, as OIG’s description of the ASP/AMP series explains. If the sales price exceeds the manufacturer price by a threshold, currently 5 percent, OIG flags the drug and passes the finding to the Centers for Medicare & Medicaid Services.
CMS is then directed to replace the sales-price-based payment with the lesser of the widely available market price, where one exists, or 103 percent of the average manufacturer price. The same OIG page says the policy applies to drug codes with complete manufacturer-price data that exceed the threshold in two consecutive quarters or in three of the previous four quarters, and that it has operated since April 2013. The program therefore works one drug code at a time and only when the data are complete.
101 drugs repriced, and $1.6 million from the latest year
The data brief, report number OEI-03-26-00080, was issued September 21, 2026 and posted September 24. Its central sentence reads: “CMS’s application of its price-substitution policy to drugs identified and referred by OIG has saved Medicare and its enrollees $78 million since 2013.” The brief adds that CMS has implemented price substitutions for 101 drugs over that span.
The most recent slice is much smaller. Substitutions for 14 drugs based on 2024 data saved $1.6 million over one year. Set against the $78 million cumulative figure, that shows the scale: the total is a thirteen-year running tally across 101 drugs, and the latest annual round is a fraction of it. OIG published no press release for the brief, and the report page names no OIG official or CMS spokesperson, so the institution itself is the only voice on the record.
Where a fifth of each reduction lands on the patient’s bill
Medicare.gov states that after the Part B deductible, a person pays up to 20 percent of the Medicare-approved amount for Part B drugs such as infusions and injections. The same page notes that coinsurance on certain drugs can be lower when their prices have risen faster than inflation. Because the percentage applies to the approved amount, a substituted lower payment limit lowers the coinsurance by the same proportion.
The deductible comes first. CMS set the 2026 Part B deductible at $283, up $26 from $257 in 2025, and the standard monthly premium at $202.90. A patient on a repriced drug pays the deductible and the premium as usual, and the benefit appears only in the coinsurance that follows. The brief does not report how many enrollees took infused or injected versions of the 101 drugs, so the per-person effect cannot be derived from it.
Thirty-one drugs the watchdog could not test
The brief also records a limit on the program itself. In its words, “Potential errors in the average manufacturer price data submitted to CMS prevented OIG from determining whether 31 drugs qualified for a price substitution.” A drug that cannot be tested cannot be referred under the program.
The data brief makes no recommendations, so no corrective step is on the record for those 31 drugs. The figures the brief does commit to are a $78 million cumulative saving, 101 repriced drugs, $1.6 million from 14 drugs in the latest year, and 31 drugs left unevaluated because of the manufacturer-price data.
Keeping Part B drug costs and Medicare decisions in one record
The Medicare Cost & Coverage Protection Kit is written for people on Medicare who take infused, injected or daily prescription drugs and need to keep track of what each one costs. A Part B drug charge is a percentage of an approved amount set elsewhere, and the same household often handles Part D prescriptions and coverage denials at the same time.
The Medicare Cost & Coverage Protection Kit includes a medication and cost tracker and the prior-authorization appeal steps, so drug costs and any coverage decision can be recorded and followed in one place.
Open The Medicare Cost & Coverage Protection Kit to set up a medication and cost tracker →
This article was produced with AI assistance and checked against the primary sources linked above.
David M. Keller is a finance writer based in Columbus, Ohio, covering personal finance and consumer-focused economic topics. He earned his degree in journalism from Ohio University and began his career reporting on local business and economic trends for a regional media outlet. Since then, he has contributed to a variety of online publications, focusing on clear, practical coverage of topics such as cost of living, debt, and everyday financial decision-making.
