Pharmacotherapy, or medication-assisted treatment (MAT), is a critical component of a comprehensive treatment plan for the pregnant woman with opioid use disorder (OUD). Methadone and buprenorphine are two types of opioid-agonist therapy which prevent withdrawal symptoms and control opioid cravings. Methadone is a long-acting mu-opioid receptor agonist that has been shown to increase retention in treatment programs and attendance at prenatal care while decreasing pregnancy complications. However methadone can only be administered by treatment facilities when used for OUD. In contrast, buprenorphine is a mixed opioid agonist-antagonist medication that can be prescribed outpatient. The decision to use methadone vs buprenorphine for MAT should be individualized based upon local resources and a patient-specific factors. There are limited data on the use of the opioid antagonist naltrexone in pregnancy. National organizations continue to recommend MAT over opioid detoxification during pregnancy due to higher rates of relapse with detoxification.