IBM Corp. has drawn fire from a worker organization for a change to its 401(k) retirement plan that cuts the frequency of company contributions to once a year.

The company will switch to matching employee contributions to their 401(k) plans twice a month to every Dec. 15, a move that “short changes IBM employees,” Alliance@IBM said on its website. The group is trying to organize workers at the company with the goal of forcing IBM to engage in collective bargaining.

While the amount that employees receive isn’t changing, workers who leave before Dec. 15 won’t get their payment for the year. Alliance@IBM, which is affiliated with the Communications Workers of America, has asked IBM management to reinstate the semi-monthly plan.

Doug Shelton, a spokesman for IBM, didn’t respond to a request for comment.