What is the impact of policy-imposed shifts in length of stay following caesarean delivery on costs, utilization, and patient outcomes? The researchers compared these effects to results from a related study examining vaginal deliveries at Harvard Community Health Plan (HCHP) between 1990 and 1998. More specifically, this project took advantage of a natural experiment created by HCHP’s recent policy change in post-cesarean length of stay requirement on the following outcome areas: 1) hospital length of stay; 2) outpatient utilization (e.g. home and office visits; 3) maternal and infant health outcomes (e.g. breastfeeding, rehospitalizations, etc.); and, 4) HMO expenditures for birth hospitalization and follow-up care. The objective of this project was to inform public and private policymakers and providers about the clinical and cost implications of changes in hospital length of stay policies after caesarean sections.