Originally Posted by
155mm
You need to get your ATP or R-ATP multi before your written expires. If it expires you'll need to take an ATP-CTP course and new written. The cost is about $5k. It would be cheaper to take a checkride in a light twin.
I think he's correct. Expired writtens used to be good forever at any 121 operation, but the new rules specifically cut that off for writtens completed under the old rules.