ALBANY — The New York Board of Regents is strengthening rules for hiring retired school superintendents to reduce “double dipping” into state pension benefits at the same time they collect paychecks.

A school district can get a waiver — known as the “211 waiver” — to allow retired superintendents to return to work if the district can find no one else competent to fill the job.

The Regents’ changes announced yesterday will require evidence that a thorough search for a replacement has been conducted and that the school district documented the selection process.

The regulations will also limit waivers to one year in most cases and require filing waiver requests before a retiree is hired.

“The waiver process must … provide well-qualified individuals to staff our schools,” the state education commissioner, Richard Mills, said. “But every administrative process can be improved. And the Regents have acted today to make our 211 waiver system better.”

The changes follow Attorney General Cuomo’s investigation into a decades-old practice of providing state pension credits to lawyers contracted to do work for school districts.

So far, several law firms and lawyers have settled with Mr. Cuomo and — while not admitting any guilt — paid back $900,000 in benefits and contributions.

Mr. Cuomo’s investigation extended to school superintendents and the 211 waiver in May.

The Regents also restricted the ability of the interim superintendent to lead the search for their replacement.