5 C.F.R. § 839.601 How do I make an election?
Title 5 - Administrative Personnel
You may make your election using the form issued by OPM. If you are an employee, your employer will provide you with this form. If you are not a current employee, OPM will provide the form.
Title 5: Administrative Personnel
PART 839—CORRECTION OF RETIREMENT COVERAGE ERRORS UNDER THE FEDERAL ERRONEOUS RETIREMENT COVERAGE CORRECTIONS ACT
Subpart F—Making an Election
General Provisions
§ 839.601 How do I make an election?