I have several exterior windows that need the glass stop trim replaced. This may be beyond my DIY ability. Would a glass company do this kind of work?

I doubt a glass company would take this on. And a window company will want to sell you new/replacement windows. Unlikely they will take on this kind of task. On that note, the wood frame of the sash looks in pretty bad shape. Not sure of the age of the windows, age of the home, the importance of it looking and functioning well, or any historic relevance of those windows? Maybe grab a mid size flat head screwdriver and probe around the bottom rail of the sash. Do you have some really soft spots? New windows may end of being a better solution than paying someone to repair/patch?

As long as the sash frame is still fairly solid, this looks like more of a handyman project; chipping and cleaning out all the rotted pieces and replacing with a matching panel molding (glass stop), sealing, and then painting. Slow tedious work and some risk of glass breaking. Again, could be a can-o-worms, keep new windows as an option if that is in your budget.

And you still have to look at any factors as to why so much rot is happening. Is it due to age? Minimal overhangs of the roof? Rainy/wet environment? No matter what course you take to fix this window issue, it will keep happening.

Thanks for the reply. The windows themselves are in good shape, no rot, just need a fresh coat of paint. The window glass stops that are rotting get direct sunlight and rain. I will reach out to someone that does handyman type work to see what they say.

That window is further down the road that you think looking at the top of that rail and the stile/rail joint, but replacing the glazing bead and getting a new coat of paint on everything will go a long way to preventing further rot.

That's a pretty easy DIY job, but agreed that a handyman type should be able to knock this out for you. If you have trouble finding someone, I would reach out to your local custom glass shop that would do glass only replacements and see if they have someone to recommend.

What is your location

One of those pics looks like it has gone from glass molding into frame

I had my painter come by and there is some rot on the lower window sash. He is going to replace that section of the window as well as the mouldings. Repairing and repainting all windows