I already have a prepaid card from last year. How do I get this year's return loaded on it instead of having a new card issued?

If you do not see the option to have your refund deposited into the same account as last year then you can select direct deposit and input the routing and account number for your card account. 

https://ttlc.intuit.com/replies/5619072

If you are referring to the Turbo Prepaid Visa Card, you can follow the link below for the routing and account number to set up direct deposit.

https://secure.turboprepaidcard.intuit.com/directdeposit/direct-deposit-enrollment