What type of visa should a single retired person obtain to stay in Thailand for a year with options to extend and travel?

Definitely a retirement Visa will do the job. But be sure to use an agent. All the paperwork and processing completed under a day. I value my time and this is definitely the way to go; fast and stress free.

Not sure where you are I was based in UK

A 12 month multi entry non O-A retirement visa is available to apply for from your own country. It’s an e visa application

You would require

12 months health insurance with minimum 4 million baht cover ( mine was £250 for annual premium from AXA)

Police check ACRO not DBS , cost £66

Health check certificate , you can get online for £20-£80 pounds ( I paid £21 ) no medical just online questionnaire.

Can’t recall cast of visa think it may have been £200 or something.

I had to prove income of over 65,000 Thai baht for a three month period before I travelled. ( uk bank statements)

No requirement to show income in Thailand or put lump sum in Thai bank.

It’s multi entry so you come and go as you please but must show insurance as well as visa when you are stamped in.

In you last month of visa if you enter with a new 12 month insurance you are stamped in for 12 months , so you can actually get 24 months out of this visa. ( second 12 months is not multi entry)

How much does the one year Exstension cost ?

Not one year ...but 9 months .

Multiple entries(important !) tourist visa .

Look into the Philippines if you haven't decided yet. Much easier visa situation and a lot more English speakers.

Non-o based on retirement. Initial visa is 90 days and eligible for multiple 1yr extensions.