The Department of Labor’s Employee Benefits Security Administration will require 401(k) plans starting Jan. 1, 2012 to clearly spell out all fees and expenses each quarter so that investors can more readily compare the costs of their holdings.

Plans will also have to give workers fee information upfront and make it available online, in a format that makes it easier for workers to comparison shop among all of the funds available in a plan. The fees will be expressed both as a percentage and in a dollar amount for each $1,000 invested.

In addition, plans must present current and one-year, five-year and 10-year performance figures, along with comparisons to appropriate benchmarks.

In making the announcement Thursday, DOL noted that “current law does not require that all workers be given the information they need to make informed investment decisions or that it is furnished in a user-friendly format. This rule will ensure that all workers have access to the information they need to make informed decisions regarding the investment of their retirement savings.”

Labor Secretary Hilda L. Solis said: “For the first time, workers will have at their fingertips important and accessible investment-related information to comparison shop among the plan options available to them.”

DOL said there are 483,000 retirement plans serving 72 million workers in the U.S.