The state Revenue Department has intercepted 529 fraudulent returns totaling almost $583,000 since tax season opened January 20.
Department spokeswoman, Molly Peterson, says most of the phony returns are the result of identity theft.
"For example, when a large corporation has its credit card information stolen from all of its customers, tax fraudsters can take that information and use it to file fraudulent tax returns."
Peterson says it's tough to find and prosecute tax return scammers because they're so good at covering their tracks.
The Revenue Department has processed almost as many individual tax returns so far for the 2014 tax year as it had this time last year; this despite extra fraud-related security and review procedures.
Peterson says almost 193,000 refunds averaging about $400 have so far been issued to Montana taxpayers.