I don't think so but for some reason it seemed like there was a different Tommy one season. Seemed as Tommy got much older he wore glasses and was tall and then the following year it seemed like he was a bit shorter and was like a "cooler" Tommy getting ready to go off to school.

Tommy Hyatt was always played by Philip McKeon.

In the first episode, Tommy was played by Alfred Lutter--who was originally in the movie 'Alice doesn't live here anymore.'

I remember seeing the pilot many years ago, and thinking how weird it was that Tommy was played by that weird kid from "The Bad News Bears" <g>. Then I saw the movie, and realized who he was. If you're used to only seeing Philip McKeon in the role, seeing Tommy played by Alfred Lutter in the pilot is a big shock.