D.C. Code § 47-1810.05
Section 8004 of D.C. Law 19-21 provided: "Sec. 8004. Applicability. This subtitle shall apply for taxable years beginning after December 31, 2010."
Applicability of D.C. Law 20-61: Section 7103 of D.C. Law 20-61 provided that § 7102 of the act shall apply for taxable years beginning after December 31, 2010.