CASTRO VALLEY -- School district union members will rally Wednesday in support of their push for a pay raise.

The school district is offering a 3 percent raise; the teachers and school support staff members are asking for 3.75 percent, according to a news release. The two groups have received a raise of 1 percent in the past five years.

The workers are represented by the Castro Valley Teachers Association and the California School Employees Association Local 52.

The teachers union also wants the district to restore supplemental Medicare payments to educators hired before 1986, when federal regulations changed. Teachers did not pay into Medicare before then. The union and district negotiated the supplemental payment so those teachers would receive the same benefits as younger workers, teachers union president John Green said previously.

The district discovered earlier this year that the benefit was deleted from the contract in 1997, even though teachers continued to receive the supplement. District officials and union representatives disagree over whether the deletion was intentional or an oversight.

The district halted the payments and began seeking reimbursement from the retirees.

The rally will be 4:30 to 5:30 p.m. Wednesday at Castro Valley Boulevard and Santa Maria Avenue. The school board meets at 7 p.m. Wednesday at 4400 Alma Ave.