Drug Copayments Frequently Surpass Prescription Drug Costs

A pile of money on top of many prescription bottles
A pile of money on top of many prescription bottles
Drug copayments often exceed prescription drug costs.

HealthDay News — Drug copayments frequently exceed prescription drug costs, with overpayments affecting 23% of all prescriptions, according to a research letter published in the issue of the Journal of the American Medical Association.

Karen Van Nuys, PhD, from the University of Southern California in Los Angeles, and colleagues examined the frequency of overpayments by comparing copayments with the national average reimbursements received by pharmacies for the same prescription for commercially insured patients (January to June 2013). Data came from a survey by the Centers for Medicare & Medicaid Services relating to the national average retail price.

The researchers found that 22.94% of the 9.5 million claims involved overpayments. The rate was significantly higher for generic versus brand drugs (28.17 vs 5.95 percent). There was a mean overpayment of $7.69, with 17.15 percent exceeding $10. Overpayments were significantly larger on brand drugs than generic drugs (mean, $13.46 vs $7.32). For 2013, aggregate overpayments totaled $135 million, or $10.51 per covered member. Hydrocodone/acetaminophen was the most commonly prescribed drug and involved an overpayment for 36.15% of claims (mean overpayment $6.94). Overpayment rates above 33% were reported for 12 of the 20 most commonly prescribed drugs.

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“Cost-related nonadherence is common and associated with increased medical services use and negative health outcomes,” the authors write. “By raising patient costs at the point of sale, overpayments may exacerbate these effects.”

Two authors disclosed financial ties to Precision Health Economics.


Van Nuys K, Joyce G, Ribero R, Goldman DP. Frequency and magnitude of co-payments exceeding prescription drug costs. JAMA. 2018;319(10):1045-1047.