Santa Clara County wasn't sticking it to taxpayers last year when it forked over $71.5 million to cover its employees' share of their pension contributions. It was sticking it to CalPERS, the state government pension system, experts say.

That's because the county has been using a rare tactic known as a "reverse pension pickup" to sweeten its employees' future retirements.

After the county kicked in millions of dollars last year to cover what employees were supposed to be paying toward their own retirements, those workers turned around and reimbursed the county $57.5 million for much of the cost.

What's the point of that? The workers don't get to see any of that money in their paychecks, but they benefit down the road because it's still considered part of their income when their pensions are calculated at retirement. The more pay an employee has amassed by the end of his career, the higher the monthly pension checks they get for the rest of their lives.

"The problem is that it's a game," said Stanford University public policy professor Joe Nation, a former member of the Assembly.

While the maneuver doesn't cost the county more in salary today, it drives up future pension costs -- a major concern with the state staring at $196 billion in future pension and retiree health care costs that it has no money budgeted to cover.

Santa Clara County isn't the only Bay Area government that offers the reverse pickup, but it's by far the biggest. County Executive Jeff Smith said the practice has existed since 2000. But after this newspaper on Friday questioned him about the county's use of reverse pickups, Smith said it is likely to come up in current contract talks. "It can be undone during negotiations," Smith said. "I believe appropriate steps should be initiated to do so."

Last year's pension reform legislation didn't address reverse pickups, said Brad Pacheco, a spokesman for the California Public Employees Retirement System.

CalPERS does not track the practice, he said. "If (agencies) negotiate this with their employees we won't necessarily know about it."

Follow Thomas Peele at Twitter.com/thomas_peele.