Houston's largest teachers' union claims that HISD is trying to push experienced teachers out the door to save money.
HISD is denying the accusation, but the Houston Federation of Teachers wants the federal government to investigate.
The union claims teacher morale has plummeted in HISD schools due to heavy handed management by the current administration.
"We've heard so many people out in the field say they are not coming back next year if they can get a job anywhere," said Gayle Fallon with the union.
Fallon said between 2009 and 2011, teacher turnover rose 27 percent and that the number is on track to go even higher this year.
And Fallon said those leaving tend to be older, better-paid teachers, and predominately, African American.
"It's the money and it's the fact that they have the old, continuing contracts," she said. "And I think the district is trying to wipe those out."
But HISD claims the district is retaining 92 percent of it's top-rated teachers.
HISD spokesman Jason Spencer said the increased turnover last year was primarily due to layoff's forced by budget cuts.
"Principals make the decision as to which positions to eliminate. The teacher's race or ethnicity or amount of money they make is not supposed to be a factor," Spencer said. "If the union has evidence that principals are using that as a factor, we encourage them to bring it forward so it can be investigated."
The union said it has asked for an investigation from the Equal Employment Opportunity Commission, and that union lawyers are preparing to file suit.