In Virginia, the governor said law enforcement would not enforce an existing law on the books that prohibits mask wearing, and encouraged all residents to follow the CDC recommendation to wear masks during any necessary trip anywhere. Virginia issued a stay home order.
In Maryland, the governor has required mask wearing in public places, public transit, food establishments, retail businesses, and other places, with the potential for fines or enforcement for those who don't follow the rules. This includes anyone over the age of nine.
The mayor of Washington, DC, has issued an order that requires customers and workers in grocery stores, hotels, food establishments, ride shares, and other places, to wear masks.
For details, this WJLA ABC 7 piece covers key points of each area's current requirements, as of April 16, 2020. Rules change frequently, and this FAQ just covers what we know them to be as of today.