Registered apprenticeship programs combine on-the-job learning through a mentor with related technical instruction. To increase employer use of and worker interest in apprenticeships, their standards—including the skills taught on the job and classroom instruction—need to reflect current occupational requirements. At this time, the US apprenticeship system has no consistent process for reviewing and—if needed— updating or even retiring apprenticeship standards in response to technological, economic, or other factors. European countries with long-standing apprenticeship systems regularly assess apprentice occupational standards to determine if they warrant modification or retirement. The review and modification approaches described in this brief can inform future efforts to design and implement a review process for American apprenticeship standards.