Notwithstanding any other provision of law, the Architect of the Capitol may accept payment or authorize an employee of the Office of the Architect of the Capitol to accept payment on the Office's behalf from non-Federal sources for travel, subsistence, and related expenses with respect to attendance of the employee (or the spouse of such employee) at any meeting or similar function relating to the employee's official duties. Any cash payment so accepted shall be credited to the appropriation applicable to such expenses. In the case of a payment in kind so accepted, a pro rata reduction shall be made in any entitlement of the employee to payment from the Government for such expenses.
Except as provided in this section or section 7342 of title 5, the Office or an employee of the Office may not accept payment for expenses referred to in subsection (a). An employee who accepts any payment in violation of the preceding sentence-
This section shall apply with respect to fiscal year 2019 and each succeeding fiscal year.
2 U.S.C. § 1873