Generally not required for stays of up to 90 days; check www.travel.state.gov for details.
Most visitors arrive by air. The city has two airports: Dulles International Airport is larger and handles most of the international flights, as well as domestic flights. Ronald Reagan Washington National Airport handles domestic services plus some flights to Canada. Reagan is more convenient, as it’s closer to the city and has a Metro stop. Baltimore’s airport is a third, often-cheaper option. It’s connected to DC by commuter rail, though it’s not handy if you’re arriving at night.
Buses are a popular means of getting to DC from nearby cities such as New York, Philadelphia and Richmond, VA. Tickets are cheap, the routes are direct to the city center, and the buses usually have free wi-fi and power outlets.
It’s also easy to reach DC by train from major east-coast cities. The fast, commuter-oriented Acela train links Boston, New York and Philly to DC’s Union Station.
Flights, cars and tours can be booked online at www.lonelyplanet.com/bookings.
The Metro is the main way to move around the city. Buy a rechargeable SmarTrip card at any Metro station. You must use the card to enter and exit station turnstiles.
Metro Fast, frequent, ubiquitous (except during weekend track maintenance). It operates between 5am (from 7am weekends) and 11:30pm (1am on Friday and Saturday). Fares are from $2 to $6 depending on distance traveled. A day pass costs $14.75.
DC Circulator bus Useful for the Mall, Georgetown, Adams Morgan and other areas with limited Metro service. Fare is $1.
Bicycle Capital Bikeshare stations are everywhere; a day pass costs $8.
Taxi Relatively easy to find (less so at night), but costly. Ridesharing companies are used more in the District.