Clarifies how the Combat-Injured Veterans Tax Fairness Act of 2016 applies to Coast Guard members when the Coast Guard is not operating as part of the Department of the Navy. It replaces vague references to “the Secretary” with specific references to the Secretary of Defense and, when relevant for Coast Guard matters, the Secretary of Homeland Security or the Secretary of Transportation, and requires those Secretaries to identify and report improperly withheld amounts within one year. The Secretary of Homeland Security must begin steps to prevent improper withholding on the date of enactment.