A new study published in JAMA has found insurance denials for brand-name drugs without generic alternatives jumped 67 percent between 2018 and 2024.
Researchers analyzed more than two million prescription fill attempts and found GLP-1 weight-loss medications faced the highest denial rates.
According to the study’s findings, nearly one-third of initial fill attempts were rejected because of formulary exclusions.
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The study also found many patients never received the prescribed drug, or a replacement, within three months of that first denial. They found that those who did obtain treatment filled their prescriptions on average 12 days after the initial rejection.
We found that insurance restrictions are increasingly shaping whether and when patients receive medications their clinicians prescribe, says Joseph Levy, PhD, an assistant professor in the Bloomberg Schools Department of Health Policy and Management and lead author of the study. While these policies may help control drug spending, they can also create meaningful barriers to timely treatment and place growing administrative burdens on patients, pharmacists, and clinicians.
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Researchers are calling for reforms to make coverage decisions faster and easier.