Table. Insulin Fills With and Without Medicare Part D Before and After the Cap on Cost Sharing^a.

	Insulin fills, mean/mo		Beginning of 2023 vs end of 2022, mean difference		Regression analysisb
	Sep 2022-Dec 2022	Jan 2023-Apr 2023	Individual group	Between-group difference	Difference-in-differences estimate for fills/mo (95% CI)	P value
All insulin fills
With Medicare Part D insurance in those aged 65-74 y	519 588	523 564	3976	18 466	21 719 (20 797 to 22 641)	<.001
Without Medicare Part D insurance in those aged 60-64 y	344 719	330 229	−14 490
Insulin fills with cost sharing of ≤$35
With Medicare Part D insurance in those aged 65-74 y	340 509	366 928	26 419	48 285	49 515 (48 480 to 50 549)	<.001
Without Medicare Part D insurance in those aged 60-64 y	242 733	220 867	−21 866

^a The data are from IQVIA’s National Prescription Audit and measure monthly prescription fills for insulin dispensed at retail and mail-order pharmacies in the US.

^b The data were adjusted for trends in insulin fills by year and calendar month.