The companies that administer retirement plans are not sure how to fill out plan tax forms this year.

Executives at the Spark Institute, Simsbury, Conn., a group that represents large retirement services vendors, have reported that finding in a summary of results from a survey of member companies that run plans with about 34 million participants.

The federal government has released regulations implementing new laws that require plans to provide more information about vendor fees, in an effort to ensure that plans are doing their best to hold down administrative costs.

Today, “a substantial majority of retirement plan service providers are unsure about how to comply with the new Form 5500 Schedule C reporting requirements,” Spark Institute executives report.

More than 70% of the participating service providers said they need more time and more guidance to comply with the new rules, institute executives found.

In some cases, half of the participants said they were interpreting a reporting rule one way, and the other half said they were interpreting the rule in a much different way, the executives say.

About 68% of the service providers said they expect plan sponsors will have to collect and report more data than they have to collect in the past as a result of the new rules.