The MOM Model supports interventions designed to improve quality of care and reduce costs for pregnant and postpartum Medicaid beneficiaries with opioid use disorder and their infants. The Center for Medicare and Medicaid Innovation is supporting awardees in eight States (Colorado, Indiana, Maine, Maryland, New Hampshire, Tennessee, Texas, and West Virginia) to implement the MOM Model with one or more care delivery partners. This first report describes how awardees and care delivery partners are implementing their MOM Model interventions, common challenges they have faced, and early successes.