The time limit should run "from the date a discriminatory wage is actually paid, not simply some earliest possible date which has come and gone long ago," said Rep. Rosa DeLauro, D-Conn.
Republicans and business advocates warned that making that change could make business executives liable for actions taken by managers who had left a company long ago.
"At the end of the day, such a loophole conceivably could allow a retiring employee to seek damages against a company now led by executives who had nothing to do with the initial act of discrimination," said Rep. Howard P. "Buck" McKeon of California, top Republican on the Education and Labor Committee.
The Supreme Court voted 5-4 to throw out a Goodyear employee's complaint that she earned thousands of dollars less than her male counterparts.
Under the court's decision, an employee must sue within a 180-day deadline of a decision involving pay if the employee think it involves race, sex, religion or national origin.
Ledbetter, a supervisor at Goodyear Tire & Rubber Co.'s plant in Gadsden, Ala., sued right before she retired. She ended a 19-year career making $6,500 less than the lowest-paid male supervisor, and she claimed earlier decisions by her supervisors kept her from making more.
The court's five most conservative members said the woman waited too long to complain. Justice Ruth Bader Ginsburg, writing in dissent for the court's four liberal members, urged Congress to amend the law.
Advocates said six months is not enough time to build a case and decide whether a lawsuit is warranted, given how secretive people are about their salaries and companies are about their decisions on raises.