With a new broadcast deal for D.C. United also comes new blackout rules. Major League Soccer runs MLS Live, which is the best sports streaming service out there, but TV agreements both with national and regional partners require that certain games not be aired on the service to protect the investment that that these partners have made. However, it also makes life more difficult for cord-cutters
National blackouts occur whenever a game is aired on ESPN/ESPN2, FS1/FS2, or Unimas. Regional blackouts are negotiated by the individual teams with their media partners, and D.C. United recently switched from Comcast SportsNet to WJLA and Sinclair Broadcasting.
Under CSN, the D.C. United blackout extended as far south as North Carolina and as far north as Pennsylvania. Under the new agreement, that footprint has shrunk dramatically, now encompassing the District of Columbia, most of non-Baltimore Maryland, and Northern Virginia.
Outside of that radius, anyone who gets MLS Live or MLS Direct Kick can watch the game on those services. In Richmond, I have the option to do both watch on TV and watch online; I do both to have my own personal replays while still supporting the new deal as it works through the kinks.
A note on the map below: Each point is at the center of each blacked out zip code. However, zip codes are fairly small, so if you're not pretty close to one you're probably not blacked out. Also, you can click on each marker to get the zip code number.