Wall Street's biggest bond dealers are starting to forecast that the U.S. Treasury will reduce the size of its debt auctions in coming months, for the first time in three years, as government revenue soars.

With the Congressional Budget Office estimating a 2013 budget deficit of $845 billion, the smallest since 2008, eight of the 21 primary dealers who trade with the Fed say Treasury may cut the amount of notes it offers that are due in five years or less as soon as July. The government hasn't trimmed coupon auctions since 2010, a year after the economy began expanding from the worst financial crisis since the Great Depression.

Limiting the supply in a market where investors are bidding about a record $3 for every $1 of debt sold may force buyers to pay more for Treasuries at a time when demand for short-term debt has pushed yields on one-month bills below zero. The dealers' outlook has shifted in response to a growing economy amid rising tax revenue and cuts to government spending.