On weekdays, you can take the MARC commuter train (the Camden Line) from Washington DC's Union Station or the Greenbelt Metro Station to Camden Station in Baltimore and walk one block to the stadium.  If it's a daytime game, you can take the MARC train home, as the last MARC train back to Washington leaves Camden Station at 6:10 pm.  If the game runs past 6 pm, MARC operates commuter bus service (the Route 701) back to Greenbelt and Union Station up to 20 minutes after the final out.  Round-trip fares to and from Union Station are $14, or $12 from Greenbelt - your MARC round-trip ticket is also valid for a return bus ride if the last train has already left.

On weekends and holidays, the MTA's Route 703 commuter bus operates between the Greenbelt Metro Station and Camden Yards, with the last bus leaving the Greenbelt Station one hour before game time, and the last bus leaving Camden Yards 20 minutes after the last out.  Round-trip fare is $12, or $6 each way.

Click here for more info and MARC train schedules.

Off-Site Links:

http://www.mtamaryland.com