5 C.F.R. § 831.402
In this subpart:
Applicant for retirement means a person who is currently eligible to retire under CSRS on an immediate or deferred annuity, and who has filed an application to retire, other than an application for phased retirement status, that has not been finally adjudicated.
Balance means the amount of voluntary contributions deposited and not previously withdrawn, plus earned interest on those voluntary contributions, less any amount paid as additional annuities (including any amount paid as survivor annuity) based on the voluntary contributions.
CSRS means the Civil Service Retirement System as described in subchapter III of chapter 83 of title 5, United States Code.
Eligible individual means a person eligible to make voluntary contributions under § 831.403 .
Full retirement status means the status of a phased retiree who has ceased employment and is entitled, upon application, to a composite retirement annuity.
Phased retiree means a retirement-eligible employee who-
Voluntary contributions means contributions to the Civil Service Retirement and Disability Fund under section 8343 f title 5, United States Code.
5 C.F.R. §831.402