Public health-public safety partnerships for post-overdose outreach have emerged in many communities to prevent future overdose events. These efforts often identify overdose survivors through emergency call data and seek to link them with relevant services. The aim of this study was to describe how post-overdose outreach programs in Massachusetts manage the confidentiality of identifiable information and privacy of survivors. In 2019, 138 Massachusetts programs completed surveys eliciting responses to questions about program operations. Descriptive statistics were calculated from the closed-ended survey responses. Thirty-eight interviews were conducted among outreach staff members during 2019–2020. Interview transcripts and open-ended survey responses were thematically analyzed using deductive and inductive approaches. Of programs that completed the survey, 90 % (n = 124/138) reported acting to protect the privacy of survivors following overdose events, and 84 % (n = 114/135) reported implementing a protocol to maintain the confidentiality of personal information. Interviews with outreach team members indicated substantial variation in practice. Outreach programs regularly employed discretion in determining actions in the field, sometimes undermining survivor privacy and confidentiality (e.g., by disclosing the overdose event to family members). Programs aiming to prioritize privacy and confidentiality attempted to make initial contact with survivors by phone, limited or concealed materials left behind when no one was home, and/or limited the number of contact attempts. Despite the establishment of privacy and confidentiality protocols within most post-overdose outreach programs, application of these procedures was varied, discretionary, and at times viewed by staff as competing with engagement efforts. Individual outreach overdose teams should prioritize privacy and confidentiality during outreach to protect overdose survivors from undesired exposure. In addition to individual program changes, access to overdose survivor information could be changed across all programs to bolster privacy and confidentiality protocols. For example, transitioning the management of overdose-related information to non-law enforcement agencies would limit officers' ability to disseminate such information at their discretion.