The current cost of an Annual Membership is $163 / year or $14.95 / month. Please see the Annual Membership page for more details.
Day passes can be purchased for $12 and 3-Day passes can be purchased for $24 within the Citi Bike app or at any kiosk (see step-by-step instructions).
Day passes cover the first 30 minutes of each trip; you can take as many 30 minute rides as you like! If you'd like to go longer than 30 minutes during a trip, there is a rate for each additional fifteen minutes the bike is in rental. As a member you get 45 minutes included in each trip instead of 30.
If you find that you are close to the 30 minute mark (or for annual members, 45 minute mark), you can dock your bike at any Citi Bike station, and wait two minutes and take out another bike.