To estimate the costs of expanding Emergency Medicaid coverage to include postpartum contraception.A decision-analytic model was developed using three perspectives: the hospital, state Medicaid programs, and society. Our primary outcome was future reproductive health care costs due to pregnancy in the next 5 years. A Markov structure was use to analyze the probability of pregnancy over a 5-year time period. Model inputs were retrieved from the existing literature and local hospital and Medicaid data related to reimbursements. One-way and multiway sensitivity analyses were conducted. A Monte Carlo simulation was performed to incorporate uncertainty from all of the model inputs simultaneously.Over a 5-year period, provision of contraception would save society $17,792 per woman in future pregnancy costs and incur a loss of $367 for hospitals. In states in which 49% of immigrants remain in the area for 5 years, such a program would save state Medicaid $108 per woman.Under federal regulations, new immigrants are restricted to acute, hospital-based care only. Failure to provide the option of contraception postpartum results in increased costs for society and states with long-term immigrants.