Department of Homeland Security 'U.S. Coast Guard' Budget Overview (Fiscal Year 2018 Congressional Justification) [open pdf - 3MB]
From the Component Overview: "The U.S. Coast Guard (USCG) operates as a multi-mission organization in support of the DHS strategic missions, goals, and objectives. Most of its assets and personnel are not dedicated to a single mission, but have the responsibility to carry out several of USCG's 11 statutory missions using risk-based decision-making to allocate these resources."
U.S. Department of Homeland Security: https://www.dhs.gov/