Budget cuts are affecting the IRS, and not just a little. Reuters reports that the strain is causing the Internal Revenue Service’s Criminal Investigation Division to reduce the number of investigators there to the lowest level in four decades. 

The division investigates everything from tax fraud and money laundering to identity theft, narcotics and counter-terrorism. But the cuts are forcing the division to scale back its fight of financial crime, which limits its ability to recover owed money that would otherwise go into government coffers.

Since the division brings in $50 billion to $60 billion a year for the government, you might wonder what the reasoning is for not properly funding it. But we then remember that Congress is responsible for funding (or not funding), and there’s our answer.

The IRS’s budget was cut by about $600 million last year as a result of the sequester, and was never brought back up. Then last month, the Republican-controlled U.S. House of Representatives voted to cut the IRS’ enforcement budget in 2015 by over $1 billion.

A proposal in the Senate, controlled by Democrats, would increase the IRS enforcement budget by $31.6 million (still $318 million below the Administration’s budget request). But with opposition from the Republican House, no one is counting on it going through.