Is there an average age of accounts that gives a person the "max" score for that part of their credit score? I have an average 5 of five years, and SW rates me as "good" in that category. Does my average age need to hit 10 years before it will be considered "Great?"
I don't think there's a max, because the FICO formula isn't linear. Because of scoring buckets, one person might have a VG or Great at 10 yrs but another might be only Good at 10 years. It would depend on other factors in your credit report in relation to others' credit. Now the Length of Credit History encompasses AAoA but it also includes the overall length of history, the length of your longest revolving TL, the length of your longest installment TL, and so on.
ETA...both EQ and TU list my AAoA at 3 yrs and the overall length of history at 10 yrs 2 months. Early in the year EQ was also at Good with a 14 yr 1 month history and a 4 yr AAoA (before my oldest fell off).