D.C. Mun. Regs. tit. 5, r. 5-A5003
The residency of each student enrolled in a District public school shall be verified by the current LEA of enrollment, or its designee, not earlier than the date results of the District's Common Lottery system are released and not later than October 5th, or ten (10) days of initial enrollment, whichever is later, for the school year that begins on or after July 1st of each year.
An LEA may require students to submit residency verification prior to OSSE's October 5th deadline, but not later than OSSE's October 5th deadline, unless the student has enrolled in the school after October 5th, in which case the student shall submit residency verification within ten (10) days of initial enrollment.
OSSE, or its designee, may investigate the residency status of a student or take other steps to verify the student's residency status if student fails to provide adequate documentation to establish residency by October 5th of the current school year or (10) days following enrollment, whichever is later.
A student matched to the LEA through the Common Lottery system shall establish residency in the District of Columbia by the deadline set by the Common Lottery system for the school year that begins on or after July 1s t of that same year. If the person enrolling the student is not able to establish residency by the LEA's initial enrollment deadline, the LEA may consider the student's space forfeited.
D.C. Mun. Regs. tit. 5, r. 5-A5003