Maybe I can amplify what Freebird, Want2retire and others have said.
At your age and with your skills, you have an enormous amount of human capital, and probably not much money or experience, so how to play this hand?
Getting a Master's degree while working full time is unimaginable to me. I know folks who have done it, but I never could. The degree will open some doors, but likely
not at your current place of employment. I hate to say it, but managers all too often pigeonhole workers, and once those opinions are formed it is almost impossible to change them. If you work for a mega-corp, you might be able to transfer to get a fresh start, but if you stay where you are my bet would be that the time you spent in getting another degree would be wasted.
Workplace politics aside, you have the value of your time to consider. Free time in your 20s is tremendously valuable, IMHO, worth much more than free time in your 60s. There are many things that you can do when young that you cannot do when older.
With that in mind, I wouldn't commit my free time to a degree program unless your lack of knowledge (not lack of degree) is preventing you having the career you want to have. My experience has been that programming is the technical field for which a degree is least important. Some of the most success programmers I know dropped out of college. Mega-corps find a way to promote exceptional programmers whether or not they have a degree.
A master's degree program (a good one anyway) will be academically oriented. They won't be teaching you the nuts and bolts, but the underlying theory. A good school will be oriented towards cutting edge research. So if you find that you lack knowledge in, say, numerical analysis or compiler theory or whatever, is preventing you from working in the field you want to be in, then going back to school is worth it. If you don't have a good idea of what you want to do, then you are going to spend all of your free time taking really hard courses that you might never use again.
If all you want to do is make more money, I think there are easier ways to do it than getting an MS. You know the drill, polish up your resume, work on your networking, be willing to move, yada, yada, yada.
Full disclosure. I have no business giving career advice to anyone. My career made Dilbert's look good. I wasn't terribly successful from a salary or management pecking order point of view, but I did get to work on fascinating problems of my own choice and I used what I learned in college to the max, every day.
Oh, I guess that I should add that I have a non-thesis master's degree, probably very much like what you are considering, but I just stayed in college an extra year to get it.
I feel like such an old f@rt, prattling on with my "wisdom". Sheesh.