Pennsylvania was singled out for praise in the report. Residents of that state will save $5.2 million in card fees each year because the state switched to a lower-fee card offered by JPMorgan.
JPMorgan declined to comment. US Bancorp and Bank of America did not immediately respond to requests for comment.
In part because of the recent improvements, the report says, prepaid cards often are the best option for people who don't have bank accounts. Those people would often pay even bigger fees to storefront check cashing services.
"A well-designed prepaid card is safer, cheaper and more convenient than paying to cash a paper check," said Lauren Saunders, one of the report's authors, in a prepared statement. But she said "it is no substitute for direct deposit to an account of your own choosing."___ Daniel Wagner can be reached at www.twitter.com/wagnerreports .