The Food and Drug Administration (FDA or Agency) is announcing the availability of a final guidance for industry entitled “Opioid Use Disorder: Developing Depot Buprenorphine Products for Treatment.” This guidance reflects the Agency's current thinking regarding drug product development and trial design issues relevant to the study of depot buprenorphine products (i.e., modified-release products for injection or implantation) for the treatment of opioid use disorder. Passive-compliance formulations such as sustained-release injectable depots and implants can provide effective treatment of opioid use disorder in a treatment paradigm that may be less subject to misuse, abuse, or accidental exposure compared to self-administered formulations such as transmucosal tablets and films. This guidance finalizes the draft guidance entitled “Opioid Dependence: Developing Depot Buprenorphine Products for Treatment” issued in April 2018.