5 CFR § 890.103 - Correction of errors.
(a) The employing office may make prospective corrections of administrative errors as to enrollment at any time. The employing office may make retroactive corrections of administrative errors that occur after December 31, 1994.
(c) The employing office may make retroactive correction of enrollee enrollment code errors if the enrollee reports the error by the end of the pay period following the one in which he or she received the first written documentation (i.e. pay statement or enrollment change confirmation) indicating the error.
(d)OPM may order the termination of an enrollment in any comprehensive medical plan described in section 8903(4) of title 5, United States Code, and permit the individual to enroll in another health benefits plan for purposes of this part, upon a showing satisfactory to OPM that the furnishing of adequate medical care is jeopardized by a seriously impaired relationship between a patient and the comprehensive medical plan's affiliated health care providers.
(e) Retroactive corrections are subject to withholdings and contributions under the provisions of § 890.502.