Hello,

If you are going to travel out of Spain with an expired card, you need an autorizacion de regreso. Even if your card is considered valid in Spain during 3 months after expiry, it is expired for travelling purposes, so I still recommend you to apply for this authorization right after you do the fingerprint at the Police Station, so you can process both applications during the same visit.

For that, you only need to have paid the tax ( 10 Euros ) showing the payment receipt , passport copy and copy of return ticket. As you know, US citizens do not need visas to enter Spain so you may be allowed in just with your passport. Anyhow, I recommend you to have the return authorization in hand.

A return authorization certificate takes 48 hours to be issued. The actual renewed card should be ready around 30 days after you did the fingerprint process.

Regards,