It’s becoming very expensive to serve as a fiduciary in this brave new world of Sarbanes-Oxley.

Insurance premiums for certain lines of fiduciary liability coverage have surged as much as 500 percent, according to the most recent RIMS Benchmark Survey.

Fiduciary liability insurance includes coverage for trustees of pension funds and trusts, as well as coverage for directors and officers of corporations.

One example: the price of policies that cover pension fund trustees have risen as much as 150 percent, according to RIMS.

Premiums for directors and officers liability insurance are up over 200 percent against last year, the third straight year of extraordinary increases.

The RIMS researchers did find, however, that the number of policy counts (which reflects the number of policies required to complete a desired level of insurance coverage), rose only slightly. “That small increase suggests that even though the costs of these policies are increasing, the supply may be catching up to demand, creating greater equilibrium in the market compared to previous quarter,” RIMS officials noted in a statement.

Other insurance categories, which have been experiencing accelerated costs over the last months, continue to see low double-digit growth. Meanwhile, some costs — including retentions or deductibles in property insurance — remained unchanged.

“The increase in fiduciary liability costs is startling, even in this hard market,” said Christopher Mandel, RIMS vice president and chief risk officer and secretary. “With the spate of lawsuits against these trustees, the resulting effect on insurance prices is understandable, but this increase is dramatic.”

The results represent data compiled from over 750 corporations.