That's not really accurate. If this is still in effect, it's the difference between in state and out of state rates, up to $10000 per year.
https://www2.ed.gov/offices/OPE/News/dcaccess.html
What types of tuition subsidies are available for D.C. residents under this legislation? The legislation authorizes two types of tuition subsidies for students. First, for D.C. residents who attend public colleges and universities anywhere in the nation, the program will pay the difference between in-state and out-of-state tuition up to $10,000 per year (with a lifetime cap of $50,000 per student).
Second, for D.C. residents who attend private colleges in the Washington, D.C. area and private Historically Black Colleges and Universities throughout Maryland and Virginia, the legislation authorizes grants of up to $2,500 per year (with a lifetime cap of $12,500 per student).
Who is eligible for these grants? To be eligible, a student must:
have lived in the District of Columbia for at least 12 months before beginning the freshman year at a college or university,
have graduated from high school or received the recognized equivalent of a secondary school diploma on or after January 1, 1998,
have begun an undergraduate course of study within three years of graduating from high school (or obtaining the recognized equivalent of a secondary diploma),
be enrolled at least half-time in an undergraduate degree or certificate program and be making satisfactory academic progress, and
not have completed an undergraduate baccalaureate course of study.