On Feb. 3, the CFPB penned a letter to the 25 largest retail banks calling on financial institutions to make lower-risk accounts more accessible to consumers to help prevent overdrafts. Now, the bureau's actions have some credit unions worried a potential rule could be on the horizon – something that could considerably impact noninterest income generation.

According to a 2012 report from the Madison, Wis.-based think tank Filene Research Institute, noninterest income has long been a hot topic for many credit union CEOs. Credit union CEOs surveyed for the report stated they are seeking a balance between creating noninterest income to support their continued operations, and charging fees that are fair and support services that add value to members.

"The tension is real," Ben Rogers, research director at Filene and the report's author, said in the report, "In Search of Member-Friendly Noninterest Income." "The credit unions are trying to walk that line between having sufficient NII and offering real value to members," the report said.