Data for Aims 1 and 2 will be archival. Patients with OUD and their propensity score-matched AUD comparators will be included for Aims 1 and 2. No other patients from these larger datasets will be included.  In/exclusion below pertain to Aim 3 qualitative interviews:  Inclusion Criteria:  VA patients with OUD who currently, or recently (within the past 6 months) receive(d) treatment for OUD from providers within Veterans Health Administration in the states of Massachusetts, Rhode Island, or New Hampshire. Non-Veteran patients with OUD (N=30) who currently, or recently (within the past 6 months) receive(d) treatment for OUD from providers outside Veterans Health Administration in the states of Massachusetts, Rhode Island, or New Hampshire. VA - OUD treatment providers who currently provide treatment for OUD within Veterans Health Administration, and have been a Veterans Health Administration provider of OUD treatment for at least one year in Massachusetts, Rhode Island, or New Hampshire. Non-VA OUD treatment providers who currently provide treatment for OUD outside of Veterans Health Administration, and have been a provider of OUD treatment for at least one year in Massachusetts, Rhode Island, or New Hampshire. OUD treatment and policy decision-makers who currently or recently (within past 6 months) hold/held positions within federal, state, or private organizations (e.g., Veterans Health Administration, SAMHSA) in which they are responsible for making and/or influencing significant decisions regarding the OUD treatment policy and/or the manner in which these are implemented.  Exclusion Criteria:  Under 18 Inability to speak fluent English Inability to provide a clear reporting of their experiences due to current influence of substances