D.C. Mun. Regs. tit. 6, r. 6-B1240
An employee who accepts a position within the District government under a different leave system without a break in service, may elect either a lump-sum payment for any unused annual leave or have such leave retained for re-crediting purposes if he or she returns to a position covered by the provisions of these regulations.
An employee who uses annual leave credited because of administrative error may elect to repay the amount received for such leave by lump-sum or installment payments, or to have such leave carried forward as a charge against later accruing annual leave, or to apply for a waiver of the overpayment under Chapter 29 of these regulations.
An employee who is separated from District government service or who enters into military service shall be entitled to receive a lump-sum payment for annual leave to which entitled.
The lump-sum payment pursuant to subsection 1240.3 of this section shall equal the pay that the person would have received had he or she remained in the employ of the District government.
The period of leave used for calculating the amount of the lump-sum payment shall not be extended due to any holiday occurring after the separation.
D.C. Mun. Regs. tit. 6, r. 6-B1240