Most shops will tell you yes. Depending on the vehicle the rotors MAY not have enough left on them to turn (one time use rotors). If you are DIYing or can talk to the mechanic who agrees you can do a “pad-slap”. New pads, wire wheel the rusty ridge at the outer/inner edge of the wear surface, scuff up the wear surface, off you go. Pad-slaps work but the break-in can be a bit weird and it usually works better if you are using a "soft’ pad, not a ceramic, carbon or whatever high performance pad. Also you need to be sure that the rotor you are leaving on will have enough metal to go another set of pads. Need spec. thickness new, current thickness, min. thickness allowed to figure this. If you are paying someone to do a pad-slap “properly” (some would say there is no proper pad-slap) you can see that it may cost close as much in added time as a new set of rotors.