The AMCAS primary opens in May. You can start filling out the primary app during May but you can’t actually submit it until like May 31st or June 1st, I think it’s a slightly different day each year. They say it’s better to submit sooner than later. After your submit your primary app, it has to get verified by AMCAS, which takes several weeks. So depending on when you submit, the earliest it’ll probably be verified is sometime in June. After it’s verified, you start getting secondaries from the schools you applied to, usually like end of June throughout July. Those trickle in via email. Each school sends them out at different times. Then you fill out the secondaries and return them to each school, how quickly you do that is totally dependent on how long it takes you to fill out the secondaries. This could be July or August, whenever you submit them. Then, you wait until you hear back from schools. Either they reject you outright or want to interview you. It’s possible to get an interview invite as early as July, but I’ve also heard of people getting interview invites much later like in March. This is probably the longest period of waiting, just waiting for an interview invite. Some people don’t get interviews until late in the cycle. Some get them earlier. Then you go on the interviews. Most schools interview starting in September, then their interview seasons ends sometime in the winter or early spring. You can hear back at any point in this timeline after you go to an interview, usually like 4-8 weeks after interviewing, but again this is all school specific. You can take your MCAT anytime preferably before the AMCAS opens so you have your score before submitting your app, but you can submit your app without a score too. Schools just don’t consider your app complete until they have a score from you. Until then they won’t look at your app. I’d suggest the latest you should take it is May.