It
gets more difficult to get insurance in complex aircraft the older you get.
Typically if you are insured and stay with the same company after 70, you just
get more requirements. I have a 75 year old in Legacy, 310 and 414.
I also have a 70 something in a 421. A 70 something in a TBM 700 and so
on.
Usually you will need to be insured with someone and stay there.
They will start requiring a medical every year and by 80 they will probably
require a second qualified pilot in the aircraft.
It didn't help that the Continental pilot that died in the
air was only 60. That will create knee jerk reactions in the industry
that old (above 60) pilots shouldn't fly commercially or complex
aircraft.