Net cost to major teaching hospitals of ACGME’s 2011 Common Program Requirements as a function of the policy’s hypothetical effect on preventable adverse events (PAEs). (a) scenario X: most programs reorganize schedules to comply with 16-hour shift requirement; small programs transfer PGY1s’ excess work to other providers. (b) scenario Y: all programs transfer PGY1s’ excess work to other providers. (In this figure, the other providers are a mixture of substitutes). Legend: —mean modeled estimate, ….95% confidence interval for mean modeled estimate.