New Mexico's highest court is mulling whether the state can cut cost-of-living increases for retired educators to help shore up the pension system's long-term finances.

The state Supreme Court is to hear from lawyers on Wednesday in a case brought by four retirees, who say the state Constitution protects their pensions from reductions like those required under a law enacted earlier this year.

The retirees contend the law gives them a "vested property right" in their retirement benefits and they are legally entitled to the cost-of-living adjustments previously promised, which would have been 2 percent this year without the change in law.

The attorney general's office and the Educational Retirement Board, in written arguments to the court, said the Constitution includes a provision that allows pensions to be modified to preserve the solvency of a retirement plan.

However, the retirees said in their lawsuit that provision only applies to retirement benefits before an employee works long enough to become vested in a pension system.

The Democratic-controlled Legislature and Republican Gov. Susana Martinez agreed on a package of pension changes this year to improve the solvency of the educational retirement program, which has a $6 billion gap between its assets and the benefits expected to be paid out in the future.