Yes, if you enroll for self plus one, you must state at the time you enroll which eligible family member you want to cover under your enrollment.
[73 FR 50184, Aug. 26, 2008, as amended at 88 FR 47746, July 25, 2023]
source: 73 FR 50184, Aug. 26, 2008, unless otherwise noted.
cite as: 5 CFR 894.202