Quick search by citation:

22 U.S. Code § 4608 - Independence and limitations

Nothing in this chapter may be construed as limiting the authority of the Office of Management and Budget to review and submit comments on the Institute’s budget request at the time it is transmitted to the Congress.
No political test or political qualification may be used in selecting, appointing, promoting, or taking any other personnel action with respect to any officer, employee, agent, or recipient of Institute funds or services or in selecting or monitoring any grantee, contractor, person, or entity receiving financial assistance under this chapter.