I took my ATP written last year for the 3rd time. The first time, I flunked it (68% or something). Studied up for another month, and then passed with a 88%. Didn't have the money to take the checkride before it expired, and it expired... I got hired to work for a 141 flight school that has a 135 gig on the side, and I took the ATP for the 3rd time and passed. It was nearly a year later that I finally got the opportunity to do my ATP checkride. I have my ASEL ATP and will do my AMEL ATP fairly soon. If you are working for a 121 or 135 operator, your written will not expire as long as you work there. Once you leave or quit, then it can expire at that point. My recommendation is get the hours in ASAP and take the checkride ASAP! That test is murder on the brain!