Originally Posted by LupineChemist

It's notoriously slow, but it's much better from flights at T4 main than T4S so unless you're very unlucky and get an M gate, I'd say plan 20-25 minutes for bags to come out.

Also, completely unmentioned, but you won't want to take Metro to get to Chamartín. There is a direct connection with the Cercanías train and on top of that, if you have the long distance train connection, it's a free transfer. There should be a QR on your train ticket you can scan to get access there for free (well, included in the price of the other ticket).

Also, I know there's a new tunnel so trains in that direction can leave for both stations, but normally Albacete trains leave from Atocha, so something to double check. Regardless, if it's Atocha, you just change at Chamartín and get any Cercanías train going in that direction.