Congressional Mandate: Part B Billing Codes for Six Drugs Included Noncovered Self-Administered Versions During January 2025 - March 2026

Why OIG Did This Review

OIG is required by statute to identify and inform CMS about billing codes for which both covered physician-administered versions and noncovered self-administered versions of a drug are used to set Part B payment amounts. For this review, OIG examined Part B payment files over a five-quarter period to identify (1) any billing codes that included covered and noncovered versions and (2) whether CMS included the average sales prices (ASPs) for noncovered versions when calculating payment amounts for January 2025–March 2026.

What OIG Found

Part B billing codes for six drugs included noncovered self-administered versions. For two of these drugs, ASPs were not actually used to set Part B payment during our review period, but the inclusion of ASPs for the noncovered versions of the drugs could affect payment amounts in future quarters.

Payment amounts for four of the six drugs included noncovered self-administered versions. In most cases, including these versions increased costs for Part B and its enrollees. For example, in the fourth quarter of 2025, Medicare and its enrollees paid approximately $15,200 for an induction dose of infused Tremfya, compared to around $14,200 had noncovered versions been removed.

Conclusion

OIG found that CMS included noncovered self-administered versions of four drugs when calculating ASP-based payment amounts; for two additional drugs, noncovered versions were included in the billing codes but payment amounts were not set using ASPs during our review period. It is now incumbent upon CMS to use its statutory responsibilities, exercising its discretion as permitted, to remove self-administered versions of any of the six drugs identified in this report from future payment amount calculations if the exclusions would result in lower payment amounts.

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