IBM ads urge us all to follow its lead and help “build a smarter planet.” Let’s hope other companies don’t follow Big Blue’s latest move: an overhaul of its 401(k) plan that shifts its matching contribution to a once-a-year affair.

Starting next year, IBM will shift its matching contribution from semi-monthly to a lump sum paid each December 31. Leave the company before December 15, and you’ll get no match at all for the year.

Retirement plan experts say it is a clever money-saving move — and one that allows Big Blue to focus its benefit resources on workers who are sticking with the company.

For loyal workers, the shift means 11 lost months every year of opportunity for dollar-cost averaged contributions and potential investment growth. And it makes the 401(k) plan less valuable to employees who leave IBM – either on their own or through layoff or disability. They’ll lose the entire match for that year.

IBM is widely viewed as an employee benefits trend-setter. The company last made retirement plan headlines in 2008 when it replaced its defined benefit pension plan with a cutting-edge 401(k) plan featuring very generous matching contributions ranging from six to ten percent – depending on hire date and years of service — low fees and access to free financial advice.

Today, IBM’s 401(k) plan is the largest private sector defined contribution plan in the country, with $37.6 billion in assets. It is the 14th-best, according to the annual ranking of top 30 plans released this week by Brightscope, which rates and analyzes plans.

“They’re a major trend-setter, so a lot of other companies will be looking very closely at this move,” said Brooks Herman, Brightscope’s head of research.

A national trend toward annual matches would be bad news for workers, especially middle- and lower-income households already finding it very difficult to build significant nest eggs through the 401(k) system.

Learn more in my column today at Reuters Money.

Tags | 401(k), Reuters