The average credit union minimum balance requirement was $969 and the average penalty fee for not meeting the requirements was $6.51. By comparison, banks had a $6,211 average minimum balance requirement and an average penalty fee of $14.76, Bankrate.com data showed.

Among credit unions offering debit cards, 15% had reward programs of some type, with the program's prevalence rising as the asset size of institutions increased. A full 40% of credit unions with $1 billion or more in assets had debit card reward programs.

Only 53% of credit unions offering debit/ATM cards charged members a transaction fee for using an ATM not owned by the credit union, the study said. Among those that charged, 42% gave members a specified number of free transactions each month before assessing a fee. However, the prevalence of that trend has declined, dropping from 48% of credit unions in 2012 and 66% in 2010.

“Setting fees is a critical task that affects sustainability for credit unions,” Jon Haller, CUNA's director of corporate and market research, said. “While credit unions want to be low-fee financial institutions, they depend on fees to cover costs, offer quality products and provide a higher level of service than their competitors. The CUNA Fees Report can help credit unions effectively set fees that provide them the highest competitive advantage.”