The United States continues to face a public health crisis of opioid-related harm, the effects of which could be dramatically reduced through increased access to opioid agonist therapy with the medications methadone and buprenorphine. Despite overwhelming evidence of their efficacy, unduly restrictive federal, state, and local regulation significantly impedes access to these life-saving medications. We outline immediate, concrete steps that federal, state, and local governments can take to change law from barrier to facilitator of evidence-based treatment for opioid use disorder. These include removing onerous restrictions on the prescription and dispensing of buprenorphine and methadone for opioid agonist therapy, requiring insurance coverage of these medications, and mandating that they be provided in correctional settings and promoted by drug courts. Finally, we argue that jurisdictions should proactively offer opioid agonist therapy to individuals at high risk of overdose, remove barriers to establishing methadone treatment facilities, and address underlying social determinants and barriers to treatment. These changes have the ability to save thousands of lives annually.