Are members of Congress too old? Twenty-four members of the United States Congress is 80 years or older. Chuck Grassley (Senator from Iowa) is 94 years old. The average age of US Congressional members is 65. Many companies have a policy that you must retire at age 65. Not for the United States Government. That's just the average age. For the members who are in their 80's, when they first started out, gas was 18 cents a gallon.