Most employer GLP-1 coverage policies are built around a clinical trigger: a diagnosis of type 2 diabetes, obesity, or a related condition that justifies the prescription. A new study published in JAMA suggests that in the postpartum population, that framework is already misaligned with how the drugs are actually being used.
Analyzing commercial insurance claims from more than one million deliveries between 2018 and March 2025, researchers from the University of Southern California and Indiana University found that the overall postpartum GLP-1 initiation rate rose from 0.08% in the first half of 2018 to 1.9% by the first quarter of 2025. The study, led by Sih-Ting Cai of the USC Schaeffer Center for Health Policy and Economics, is described by the authors as the first US analysis of postpartum GLP-1 initiation using commercial claims data. It was funded by the National Institute for Health Care Management Foundation (NIHCM). Cai disclosed that an immediate family member is employed by Novo Nordisk.
In the second half of 2024, women with overweight or obesity accounted for 40.4% of postpartum GLP-1 initiators. Women with no documented predelivery qualifying diagnosis accounted for 20.7%, and women with gestational diabetes for 20.6%. Women with type 2 diabetes, the group most unambiguously covered under standard employer GLP-1 policies, represented only 18.3%.
Among the 1,155 initiators who had no qualifying predelivery diagnosis, 55.2% had one recorded between delivery and their first fill, most commonly overweight or obesity. The remaining 44.8% had no qualifying diagnosis recorded anywhere in the claims data.
That last group is where most employer GLP-1 authorization frameworks will stall. Prior authorization requirements, which are widely used across employer plans that have increasingly tightened GLP-1 coverage over the past year, are typically built around diagnosis codes. A postpartum prescription with no matching code will trigger a review that the claims data alone cannot resolve.
Most postpartum initiation did not occur immediately after delivery. The study found that 61.6% of women filled their first prescription between months three and six postpartum, with a median time to initiation of 108 days. That window overlaps with the period when many women are still breastfeeding. The study could not observe breastfeeding status, which is a named limitation, and current FDA labeling advises against GLP-1 use during lactation due to limited safety data. Claims data offers no way to flag that distinction.
The timing also matters for how benefit advisors interpret the data when reviewing employer plan design. An initiation that occurs at month four postpartum looks identical in a pharmacy claim to one at month four for any other commercially insured woman. Nothing in the claim signals postpartum status, gestational diabetes history, or lactation. Plans that are simultaneously managing GLP-1 costs as one of their fastest-rising pharmacy expenses now have a population-specific utilization pattern that their current coverage criteria were not designed to address.
The study's cohort was limited to commercially insured women, which is also the population through which most postpartum GLP-1 prescriptions flow. The authors note that the 2024 US initiation rate was similar to rates previously reported in Denmark, despite differences in healthcare systems, pricing, and coverage structures. That parallel suggests the postpartum trend is not a product of any single coverage policy but reflects a broader shift in prescribing behavior that is reaching employer-sponsored plans regardless of how those plans are designed.
The study's limitations are worth naming alongside its findings. Claims-based diagnoses may undercount overweight and obesity relative to measured BMI. Preconception GLP-1 users who paused during pregnancy may have been misclassified as new postpartum initiators given the 180-day lookback window. And because the data run only through September 2025, they may not capture more recent prescribing changes.
What the data do capture, through September 2025 across more than a million commercially insured deliveries, is a postpartum prescribing pattern that is growing rapidly in a population whose clinical profile does not fit neatly into the coverage categories employers have been building and revising for the past three years.
