Bill, I've sometimes gotten good advice from municipal Building Inspectors. Senior Centers also sometimes have lists of contractors, but others don't, not wanting to get involved with referrals.
You might also search online for "mobility contractors" in your zip code, which I just did:
I've found that contractors often don't do just one function (unless it's plumbing or electrical, or other major trade), but that some of these smaller contractors provide related services.
Alzheimer's Association also maintains lists; I got names of disability contractors from them.
As to individual reputations and competence, I can't speak to that, but you can ask for photos of projects, draw your own specs and have them review and cost them out, contact references, ask for info on homes on which they've worked and do a drive by to see if you're impressed.
Another option might not yield immediate results, but if you have time, check your local Area Agency on Aging as well as various municipalities in the area to see if they hold Senior Expos or Caregiving Expos. The AAA used to do that in my area but no longer does. However, I got brochures and information from mobility contractors who had display booths at various expos.
You could also expand beyond railing construction to handymen or porch installation contractors who could build them as well,
area codes (in the USA) have 3 numbers your profile states TN. So I am guessing that is where you are. Homeadvisor.com would be a good place to start. Another place to check is the local Senior Center. Sometimes they have a list of people that will do work for seniors. Might also want to look at a ramp and not just railing just in case a ramp is necessary later.
You might also search online for "mobility contractors" in your zip code, which I just did:
https://www.google.com/search?source=hp&ei=ZmjwXY_ZNpKKtQXJnZ6IBA&q=mobility+contractors%2C+zip+code+47714&oq=mobility+contractors%2C+zip+code+47714&gs_l=psy-ab.3...9272.33983..34227...10.0..1.261.3836.35j6j1......0....1..gws-wiz.......0i131j0j0i10j0i22i30j0i13i10j0i13i30j0i13i5i30j33i160j33i22i29i30j33i299.CMwMw9Dcqj0&ved=0ahUKEwiPpLCo2azmAhUSRa0KHcmOB0EQ4dUDCAs&uact=5#spf=1576036490883.
and handicap contractors:
https://www.google.com/search?ei=iWjwXcLzK4_-tAWp36rQDw&q=handicap+contractors%2C+zip+code+47714&oq=handicap+contractors%2C+zip+code+47714&gs_l=psy-ab.3...81476.82675..84091...0.1..0.91.661.8......0....1..gws-wiz.......0i71.aDMM325kfl4&ved=0ahUKEwiC3P242azmAhUPP60KHamvCvoQ4dUDCAo&uact=5#spf=1576036576807
And the last link provides a hit that might be a good starting point:
http://www.sortfix.com/disability-ramp-construction/in/evansville.php.
I've found that contractors often don't do just one function (unless it's plumbing or electrical, or other major trade), but that some of these smaller contractors provide related services.
Alzheimer's Association also maintains lists; I got names of disability contractors from them.
As to individual reputations and competence, I can't speak to that, but you can ask for photos of projects, draw your own specs and have them review and cost them out, contact references, ask for info on homes on which they've worked and do a drive by to see if you're impressed.
Another option might not yield immediate results, but if you have time, check your local Area Agency on Aging as well as various municipalities in the area to see if they hold Senior Expos or Caregiving Expos. The AAA used to do that in my area but no longer does. However, I got brochures and information from mobility contractors who had display booths at various expos.
You could also expand beyond railing construction to handymen or porch installation contractors who could build them as well,
Homeadvisor.com would be a good place to start.
Another place to check is the local Senior Center. Sometimes they have a list of people that will do work for seniors.
Might also want to look at a ramp and not just railing just in case a ramp is necessary later.