Gov. Mark Sanford on Thursday renewed his call to tie bonus pay guaranteed to teachers who achieve a national credential to accepting reassignment to work in underperforming schools.

“There’s no question that having highly qualified teachers is a key component of educational achievement, and I’d give great credit to every teacher in this state for what they do day in and day out in educating our students,” Sanford said in prepared remarks released by his office.

“But the fact is when you have consistently underperforming schools ... we’re clearly not doing enough to put teachers where they’re needed most. These latest test scores show that it’s time to stop studying this issue and start acting,” Sanford said.

As part of school reform that emerged in the late 1990s, the Legislature created a $7,500 annual pay incentive for teachers who earn National Board Certification, a voluntary yearlong process that requires them to write thesis-style papers, have their classes videotaped for peer review and pass a graduate-level exam. A national certificate is good for 10 years, which means a recipient could earn an additional $75,000 above his or her annual pay over that period.

Some school districts, including most in the Columbia area, offer an additional stipend of several thousand dollars on top of the state bonus.

South Carolina has more than 3,600 national-credentialed educators teaching in 84 of the state’s 85 school districts, said Ann Byrd, director of the state’s teacher recruitment center. Bamberg 2 is the only district that has no teacher with the certificate.

Sanford’s proposal would affect only teachers who are newly certified.

Reach Robinson at (803) 771-8482 or brobinson@thestate.com