The result changes with the drug group
A Medicare Part D study publicly released October 5 finds a pattern that resists a blanket rule about pharmacies owned by health-plan companies. Affiliated pharmacies generally had lower payments and patient cost sharing in the examined groups, but some expensive drugs produced higher patient costs.
GAO studied 2023 data from four large, vertically integrated plan sponsors representing more than 40 percent of Part D enrollment. Their affiliated pharmacies accounted for 24 percent of utilization and 28 percent of payments in the analysis. The study is not a census of every plan or a current quote for a prescription.
Common prescriptions and expensive prescriptions differ
For at least 94 percent of the 100 most-used drugs, predominantly generics, both payments and cost sharing were lower at affiliated pharmacies. Among the 20 drugs with the highest payments per 30-day supply, however, half had higher cost sharing at affiliated pharmacies, with differences reaching about $340.
Those two findings can coexist. A high-volume generic comparison describes a different purchasing problem from a small group of expensive medicines. Ownership does not by itself tell a beneficiary which pharmacy is cheaper for the drug they take.
What the comparison can—and cannot—decide
The practical comparison is the exact medication, strength, quantity, plan and pharmacy. This research does not establish that a specific person should change pharmacies or prescriptions, and Part D benefit rules have changed since the 2023 data period.
The ownership links create a reason to examine incentives and costs, but the reported differences do not independently establish unlawful steering. GAO’s drug-level results are more informative than either an assurance that affiliated pharmacies always save money or an accusation that they always charge patients more.
Sources and further reading
GAO-26-107393, published September 3 and publicly released October 5, 2026 ↗
Full report: methods, drug groups and cost-sharing comparisons ↗