Citing rising medical costs, California Insurance Commissioner Steve Poizner recommended Friday that the state’s insurers charge employers 5 percent more for workers’ compensation premiums.

In making the recommendation for the increase next year in the benchmark rate for workers’ compensation insurers, Poisner rejected an earlier recommendation from state actuaries at the Workers’ Compensation Insurance Rating Bureau for a 16 percent increase.

“Last year, experts predicted that loss expenses would increase dramatically. They did not,” Poizner said. “Given the (lack of) accuracy of past forecasts, I will wait for clear and compelling data confirming such increases before significantly increasing the benchmark.”

Nonetheless, it’s still the first recommended increase in the benchmark in five years. In his last review of workers’ compensation insurance rates in January, Poizner recommended no change in the benchmark. Prior to that, Poizner recommended a 14 percent decrease.

Under the 1993 workers’ compensation insurance deregulation law, the state does not set the rates insurers can charge employers for workers’ compensation insurance. Instead, the Insurance Commissioner recommends a benchmark rate on which insurers generally base their premiums.

Poizner noted that even with the 5 percent upward adjustment, the benchmark rate has fallen 63 percent since its high in 2003.