what is the exact definition of "n.a." at the end of a bank's name?

National Association

As another clarification, all National Banks (and only National Banks) must have the word National in their name. Many have it incorporated as "First National Bank of XXX"

Some banks use the N.A. at the end and there are other variations such as the original Bank of America N.T. & S.A. (National Trust and Savings Association). It means they are chartered and examined by the Office of the Comptroller of the Currency.

Great piece of banking trivia!! I went to FDIC's institution directory and found a Fourth Federal Savings Bank in NY and a Fifth District Savings and Loan in New Orleans. I did not find a Sixth, Seventh, Eighth, Ninth, Tenth, or Eleventh. Someone else can check for higher. This should be a Jeopardy question or Millionaire question.

I forgot to mention in my last post that neither of the above are "National."