Charles Schwab Corporation continues to tout low fees with the announcement of first-year results for Schwab Index Advantage.

By tracking index-based mutual funds in particular, Schwab Index Advantage lowers costs on the overall 401(k) platform. The industry's only index-based retirement platform is a precursor to the ETF-based 401(k) plan that Schwab Retirement Plan Services announced in January 2012, which will launch toward the end of this year, said spokesman Eric Hazard.

"We launched this first to get sponsors comfortable with the index-based platform versus actively managed funds. Now that we're seeing the uptake there, this should serve as a lead-in to the all-ETF index platform," Hazard explained.

Regarding the benefits of Index Advantage, Steve Anderson, executive vice president of Schwab Retirement Plan Services, said in a press release, "We are seeing the effective implementation of this new breed of 401(k) plan through sharply lower investment expenses and markedly higher rates of advice usage."

According to Schwab, participants enrolled in Index Advantage have experienced an average 77% decrease in their operating expense ratios for investment in their 401(k) plans to $14.78 per $10,000 invested. The average pre-Index Advantage hovers around $65.11 per $10,000 invested.

Nearly 90% of Index Advantage participants receive third-party advice to help manage their 401(k) investments, versus 4% electing to receive such advice prior to the transition to Index Advantage.

So far, Index Advantage has logged 50 sponsors representing $4 billion in 401(k) assets, a "great pickup" considering the platform has only been available for one year. He would not provide additional details regarding projected rate of adoption going forward.

"It's a validation of the all-index mutual-fund platform," Hazard added. "Sponsors recognize the value of paying less."

Meanwhile, the delay on the launch of Schwab's ETF-based retirement platform is due to the need for a brand new recordkeeping model for the platform. Once the platform launches, Schwab will be the first and only major provider to offer an all-ETF retirement platform.

Charles Schwab Corporation currently boasts 1.6 million corporate retirement plan participants and $2.01 trillion in client assets as of Jan. 31.