WASHINGTON — The government is revising its definition of what it means to farm, meaning some people who receive farm subsidies but don’t do any of the work would receive less government cash.

Congress charged the Agriculture Department last year with creating a new definition for what it means to be “actively engaged” in farming, the criteria to receive some subsidies. USDA proposed Tuesday farms must document their managers put in 500 hours of substantial management work annually or 25 percent of the time necessary for the success of the farming operation to qualify.

“We want to make sure that farm program payments are going to the farmers and farm families that they are intended to help,” Agriculture Secretary Tom Vilsack said.

However, the rules only apply to some farm businesses. Congress exempted family owned entities, which make up some of the country’s largest farms, as part of a provision in the wide-ranging farm bill.

USDA said as many as 1,400 operations could lose eligibility under the rules, saving around $50 million over a three-year period.