The ORCA card is all you need to pay your fare on buses and trains in the Puget Sound region. After you load E-purse (electronic purse) value or a monthly pass on it, your ORCA card works like cash or a pass, automatically tracking the value of different fares and transfers so you don't have to.
ORCA adult and youth cards cost $5*
Once you have a card, you can add between $5 and $300 onto the card's E-purse, which works similarly to a pre-paid debit card and deducts the correct fare each time you tap. When the card's E-purse balance gets low, just add additional value.
If you are a frequent rider, you can add a regional monthly pass good for an unlimited number of trips on designated transit agencies during the valid calendar month.
You can have E-purse and a monthly pass on the same ORCA card. The E-purse can be used in combination with a pass in the event the pass value is less than the fare for a ride.