The Coastal Communities Ocean Acidification Act of 2023 amends the existing Federal Ocean Acidification Research and Monitoring Act to strengthen collaboration between the National Oceanic and Atmospheric Administration and coastal communities affected by ocean acidification. The bill requires NOAA to establish ongoing engagement mechanisms with state and local governments, Indian Tribes, Native Hawaiian organizations, fishing industries, and scientific experts to ensure that research and monitoring efforts address real-world management and adaptation needs. It also expands the advisory board membership to include representatives from Indian Tribes and Native Hawaiian organizations, and mandates the development of policies for regular consultation with these groups. Additionally, the bill directs NOAA to collaborate with communities conducting vulnerability assessments, research planning, and climate action plans related to ocean acidification, with priority given to underserved populations. The legislation contains no specific funding amounts or implementation timelines beyond a requirement that an advisory board develop tribal engagement policies within one year of establishment.