The age for exemption from jury duty varies by state. Typically it’s. 70, 73 or 75.
There is no upper age limit for federal jury duty, but generally if you are 70 or older, you can request to be excused and it will be granted.
When I was teaching many years ago, one of my colleagues was always smug about jury duty. Her husband was one of the leading defense attorneys in town. No prosecutor ever wanted her on their jury. She been called 3 or 4 times and had always been dismissed during voir dire.
Then she got a summons for federal jury duty. Her husband’s name/reputation didn’t carry any weight there. Not only was federal duty in the state capitol –a 70 minute drive each way– it also lasted 6 months whereas local jury duty was for 2 weeks. She was really peeved about that.
(For federal jury duty if you lived more than 100 miles from the federal courthouse, the feds would put you up in a hotel if you had to be in court the next morning. But she only lived 90 miles away so she had to drive up and back every day if she needed to be in court to hear testimony. She was very, very annoyed. )