This, I actually disagree with, because there will also be a lot more competition from younger/cheaper "talent."
IMHO a mid-career person needs to create a niche where their value is more than just writing code. e.g. bring code to an area where you already have expertise, or bring your expertise to the code. Random example: If you've been working as a restaurant manager, what tools would have made that job easier?
B
I see this discussion has spilled onto a second page, so I'll be brief and just make some bullet points:
1. Yes, there is an age bias and has been for quite a time (not just software, but engineering in general);
2. If you want to program, your completed work / samples of work will probably be more important than any degree or qualification;
3. As you are likely aware, being mid-life and mid-career already, there is a lot more than just the work that makes a career and job fun/interesting;
4. If you are really looking at a total career change, have you ever thought about taking vocational interest tests? When I talk to people who have taken such testing (good tests, not the online quickie stuff, or people moonlighting on the side doing such things) have uniformly told me that it was invaluable for them. If I ever decided to change careers (currently, love my career, but don't love the job), I would probably do that first.
Good luck!