The standard Metro fare card is a paper card with a magnetic strip and can be purchased for any amount.

Note: Do not keep your metro card near a credit card or your cell phone. It may become demagnetized and unusable.

To use the fare card:
• Insert the card into the slot in the front of the fare gate on your RIGHT.
• The card will “pop up” in the top of the fare gate.
• Take the card out and the gate will open
• You will use the card everytime when you enter and leave the Metro platform.

Note: there are some wider fare gates intended for handicapped use. On these, the card is inserted and removed from the same slot in the front of the fare gate. You can see pictures of what this looks like.

Fare Information
If you use up the value on the card such that the value is zero when you exit, the gate will NOT return your card. If you do not have enough value left to exit, use an ADD FARE machine near the gates. Insert your card, and the machine will tell you exactly how much extra you need to depart the station.

Here's information about how to purchase a fare card at a station. Note especially the advice to use small bills if not credit cards.

SmartTrip Cards
There is also a permanent plastic rechargeable SmarTrip card. The minimum charge for these is $10.00 ($5 fare and $5 for the card itself). If you plan to park at a Metro parking lot with multi-day parking, you MUST have one to exit the parking garage. SmarTrip cards may be purchased at the Metro stations wherever there is a parking lot. Note: you MUST have enough money on the card to be able to exit the lot.

Metro Etiquette
• Stand on the right, walk on the left. Commuters on the way to or from work often walk up or down the moving escalator stairs.
• When you get to the top or bottom of the escalator, DON’T STOP... KEEP MOVING. Otherwise you may get run over.
• There is no eating or drinking at all (not even water) in the stations, on the platforms, or in the train cars.
• When boarding the train, please allow the people exiting to leave first before entering the car.
• If the trains are crowded and you have to stand, please try to move into the car away from the doors as much as possible. This is especially important during rush hours.

You can get more information here.