D.C. Mun. Regs. tit. 6-B, § 1242
1242.1 An agency head shall grant sick leave to an employee under any of the following circumstances:
1242.2 When any of the circumstances set forth in section 1242.1 of this section occurs within a period of annual leave, an agency head may, at the employee's request, convert annual leave to sick leave.
1242.3 Annual leave may not be substituted for sick leave that has been applied for and granted.
1242.4 An employee shall file a written application for sick leave within such time limits as the agency head may prescribe.
1242.5 An employee shall request sick leave in advance for a pre-scheduled appointment for medical, dental, or optical examination or treatment.
1242.6 An agency head may grant sick leave only when supported by a medical certificate or appropriate document signed by the employee.
1242.7 For an absence in excess of three (3) workdays, or for a lesser period when determined necessary by an agency, the agency may require a medical certificate, or other administratively acceptable evidence as to the reason for the absence.
SOURCE: Final Rulemaking published at 54 DCR 11538 (November 30, 2007).