[Code of Federal Regulations] [Title 5, Volume 1] [Revised as of January 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 5CFR319.402] [Page 192] TITLE 5--ADMINISTRATIVE PERSONNEL CHAPTER I--OFFICE OF PERSONNEL MANAGEMENT PART 319_EMPLOYMENT IN SENIOR-LEVEL AND SCIENTIFIC AND PROFESSIONAL POSITIONS--Table of Contents Subpart D_Recruitment and Examination Sec. 319.402 Scientific and professional positions. (a) ST positions are filled without competitive examination under 5 U.S.C. 3325. (b) ST positions are not subject to the citizenship requirements in 5 CFR part 338, subpart A. Agencies, however, must observe any restrictions on the employment of noncitizens in applicable appropriations acts. (c) ST employees acquire competitive status immediately upon appointment. They are not required to serve a probationary or trial period.