You floss regularly, yield to oncoming traffic and use your credit cards judiciously, dutifully paying off your balance every month.

You may believe that your exemplary behavior shields you from unexpected credit card fees. Sadly, that is no longer the case.

Starting next year, Bank of America will charge a small number of customers an annual fee, ranging from $29 to $99. The bank has characterized the fee as experimental. But card holders who have never carried a balance or paid late fees could be among those affected.

Citigroup, meanwhile, has started charging annual fees to card holders who don’t put more than a specific amount on their cards, typically $2,400 a year. Other banks are charging inactivity fees if customers don’t use their credit cards during a specific period of time. You heard that right: You could be spanked for staying out of debt.

USA Today: Pay your bills on time? There’s a charge for that.

Also: Citibank is randomly closing credit cards without warning.