SS switched them over automatically at age 65.
SS gave them the greater of the two possible benefits.

SS looked at lifetime earnings including the ssdi years and compared it to just the ssdi they were receiving, and gave them the better of the two.
For this person I knew, the lifetime earnings provided a better benefit so that was what they started receiving.

Now this was like 7-8 years ago and the person's birth year made them eligible at 65. YOUR CASE AND Specifics and current law may be different.

Every case is different. Don't compare yourself to what you may know about others. That's the major thing I have learned about social security over the years and various cases I was privy to.

Once my disability determination and award came through, I didn't have to be evaluated again. I had a regular provider for my regular stuff but my evaluation date for eligibility was seven years from my award date. That's called full disability. I was on that until I 'aged out' at 67 and all my case stuff was transferred to regular retirement social security, since I was too old to be expected to work.

The only thing that changed was the state kicked me off of medicaid because I had received an inheritance during the covid thing so when they were able to reset the medicaid rolls, I no longer qualified for the state thing.

I guess some people have partial disability, that may require more frequent evaluations but that may also depend on your age if you are 60 or over. That's what I gathered from the paperwork.

That's all I can tell you, nothing changed except the agency sponsoring my funds. The date the money comes is the same as is the amount.

change of status. There are no required exams. You now have the disability of aging.