Ever since the game’s release, players have been asking if it’s possible to change the team they picked for Pokemon Go. When everybody first started playing, they had no idea what teams would be dominating their areas and which teams would fall through the cracks. To be very blunt about the question, no. You cannot change your Pokemon Go team unless you create a brand new account and go through everything all over again.
That being said, it might be a change for the future. Niantic has never said that players will be able to change teams, but their wording might be hinting at a possibility in the future. On the frequently asked questions page for the site, Niantic answered the question “How do I change my team?” by saying, “At this time, it is not possible to change your team.” Does that imply that maybe one day we will be able to change who we align with?
I would say it’s highly unlikely. I mean, that kind of defeats the whole purpose of the team system. If you have a lot of Team Mystic around you, and you chose Valor, why would they allow you to switch to Mystic? That would just cause the entire area to change to one team, preventing anybody from ever taking over a gym. At the end of the day, I like the team system the way it is and I hope that they don’t allow players to do any switching!