WASHINGTON — Distinctly unpopular among voters and a scant presence in most congressional districts, federal workers have become an easy target in the hunt for budget savings.

Their retirement programs are notably generous compared to the norm in private industry. But for federal workers hired after 2012, the pension program is turning less generous.

Most federal civilian employees hired beginning in January will contribute 4.4 percent of their pay to their pension plans under the House-passed budget bill the Senate is expected to approve this week. Government workers hired in 2013 will continue paying 3.1 percent of their gross pay to help cover their pensions; those on the federal payroll before then, 0.8 percent.

“It’s insane they should be expected to fund government,” said Jackie Simon, policy director for the American Federation for Government Employees, the union representing 630,000 federal workers. “It’s a big country. The burden should be spread more broadly.”

But with pensions for nongovernment workers on a path toward extinction, federal employees get little sympathy from some experts.