Office of Personnel Management brass say Friday's column, about the changes the Reagan administration can make in the career service, was a trifle alarmist. It pointed out that following a mandatory 120-day grace period SES personnel can be reevaluated, transferred or whatever by their political chiefs. I wasn't predicting wholesale bloodshed on the 121st day, but attempted to explain the rules (set up by the Carter administration) that make high-level housecleaning easier than ever before. Be that as it may, here is the official word on the subject of the 120-day time period as spelled out by OPM's general counsel, Margery Waxman. It says in part: ". . . Sections (5 U.S.C. 3395 (e) and 5 U.S.C. 3592 (b) . . . provide that an SES career-appointed employe may be neither involuntarily reassigned nor removed within 120 days after an appointment of (1) a new agency head; or (2) the career appointee's most immediate supervisor who is a noncareer appointee. Thus the issue presented is whether, in those cases where a new aency head and a new noncareer supervisor are appointed within 120 days of each other, the agency must wait 120 days from the latter appointment to reassign or remove a career SES employe.

"We have concluded," the OPM advisory says, "that a new head of an agency or a new noncareer supervisor can involuntarily reassign or remove a career SES employe 120 days after the appointment of the official who effectively takes the action, regardless of the date the other official was appointed. This action, however, must be based on the knowledge of the two sections and on the associated legislative history. . . ." Seems to me that, whenever you start the 120-day countdown, the fact is that there is a countdown now for the first time, and that is what is making the SES types jittery.