5 U.S.C. § 3301: Civil service; generally

(a) In General.—The President may—(1) prescribe such regulations for the admission of individuals into the civil service in the executive branch as will best promote the efficiency of that service; (2) ascertain the fitness of applicants as to age, health, character, knowledge, and ability for the employment sought; and (3) appoint and prescribe the duties of individuals to make inquiries for the purpose of this section. (b) DOD Procedures.—The President may authorize the Department of Defense to determine the qualification, examination, and assessment procedures for positions in the competitive service based primarily on job-related competencies and skills, including the use of structured interviews, technical evaluations, or skills-based assessments, and alternative assessments.