You may use your Maestro card anywhere in the US that accepts MasterCard debit cards. You must physically have your card present and enter your PIN. However, Maestro cards may not be used in the US for online purchases. All US issued debit MasterCards work internationally on the Maestro and Cirrus networks.
Maestro is a brand of debit card issued by Mastercard. Maestro cards can be used for in-store payments and for withdrawing cash at ATMs. Most Maestro cards also allow online payments, depending on the associated bank.