The Senate version of the farm bill would spend $963 billion over 10 years while the House bill would spend $950 billion. The farm bill expired last year, but a temporary extension keeps the program running until September.
The Congressional Budget Office recently determined that the bills in Congress would save less money than earlier estimated.
The new figures show that the Senate version of the farm bill, which the C.B.O. said last year would save $23 billion over 10 years, would save only $13.1 billion. The House bill would save $26.6 billion instead of the $35.1 billion estimated last year.