People with substance use disorders (SUDs) are increasingly admitted to general hospitals; however, many hospital systems lack both formal structures and skilled staff to provide high-quality care for inpatients with SUDs. Inpatient addiction consult services (ACSs), which are increasingly being implemented around the country, are an evidence-based strategy to add focused care for people with SUDs into the general medical setting. In 2018, New York City Health + Hospitals (H + H) launched an ACS program called Consult for Addiction Care and Treatment in Hospitals in six hospitals, supported by a team of addiction consult experts to deliver teaching and technical assistance (TTA) for the Consult for Addiction Care and Treatment in Hospitals ACSs. This commentary describes the TTA, which included site visits, introductory educational lectures, case conferences, ad hoc support, implementation assistance, and the creation of an addiction care guide. Similar TTA services could be used in the future when hospitals or systems want to launch novel clinical programs.