I just went to Best Buy and they do have a few cases for the iPhone 13 Pro Max and they will fit the 12 pro max just fine but your iPhone 12 promax case will not fit with the iPhone 13 pro max because of the camera window is larger. The buttons are in the same place and I’m pretty sure the new iPhone 13 Pro Max will be .2 mm thicker I believe, y’all can correct me if I’m wrong. I picked up an OtterBox commuter at Best Buy. Kind of a purple/plum color that will go well with the blue I think.