5 C.F.R. § 900.706
(a) General.
(3) The prohibition against discrimination in employment applies to the following activities:
(b) Reasonable accommodation.
(3) In determining pursuant to paragraph (b)(1) of this section whether an accommodation would impose an undue hardship on the operation of the recipient in question, factors to be considered by OPM include:
(c) Employment criteria.
(d) Preemployment inquiries.