Is this a structural brace?

[balata9999]

This short piece of wood with the martin logo came unglued in my guitar. I was going to line it back up and glue it back with some titebond but wanted to see if that was ok or should I take it to a pro. It has a crack in the middle of it and is in two parts. I think it got knocked loose when changing a battery.
https://imgur.com/a/yfI9J

[phavriluk]

If OP is referring to the strip of crossgrained wood running right down the middle of the back on the inside, while it's not a brace as such, that wood was used to reinforce the joint where the two back plates meet. Now's where questions get interesting. Did OP buy this guitar new? Is it registered to him at Martin? We're looking at what might be a manufacturing defect which might well be covered by Martin's lifetime warrantee to the original owner. My opinion, I wouldn't do the repair myself if the guitar was under warrantee, I'd let Martin do it and take a look around while they're at it. The rest of the reinforcement may well be short of glue, too.

[Athens]

Yes, not a brace, as such, but it strengthens the seam between the two halves of the back. If that one came loose it's a good idea to have everything checked. If it's warranty, so much the better.

[balata9999]

Ok thanks. Yes I am the original owner so I do have warranty. I'm thinking of having everything checked out anyway. That answers me questions. I appreciate it.