The Strategic Plan for Federal Research and Monitoring of Ocean Acidification will guide federal research and monitoring investments that will improve our understanding of ocean acidification, its potential impacts on marine species and ecosystems, and adaptation and mitigation strategies. This is the second Strategic Plan and is an update to the first version released in 2014. The Strategic Plan contains objectives and action items organized around seven thematic areas: (1) research; (2) monitoring; (3) modeling; (4) technology development; (5) socioeconomic impacts; (6) education, outreach, and engagement strategies; and (7) data management and integration. Some highlights of the plan’s action items include: Expand coastal acidification monitoring in the nearshore and estuaries Expand certified reference material production for seawater pH measurements Identify and support human communities vulnerable to acidification through co-production of knowledge Develop synthesis products at coastal and regional scales to guide model development The plan was developed by the Interagency Working Group on Ocean Acidification as part of the Federal Ocean Acidification Research and Monitoring Act of 2009 (FOARAM Act; 33 U.S.C. Chapter 50, Sec. 3701-3708).