401(k) investors aided by professional investment advice—be it in the form of a target-date default investment, managed accounts or bona fide online advice—experience returns averaging nearly 2% better (186 basis points) than those who do not receive such help, according to a joint study by Hewitt Associates and Financial Engines.

Titled, “Help in Defined Contribution Plans: Is it Working and for Whom,” the report analyzed the portfolios of 400,000 investors. While the snapshot results year-by-year are not that impressive, the companies emphasized that by age 65, a 45-year-old  who uses professional investment help will have a retirement savings account 47% larger than someone who didn’t get the help. The difference is even more dramatic for the 40-year savings horizon of a 25-year-old, who ends up with 103% more.

The report also found that younger, less-tenured investors are more likely to use simpler, target-date funds, while older workers are more likely to use managed accounts to meet their more numerous and complex responsibilities and needs.

According to the study, participants who use professional investment help follow a more appropriate glide path, where risk starts out higher early in their careers and “glides” downward as they approach retirement. Also, their portfolio allocations were more efficiently invested.

“Employers offer workers investment help like target-date funds, online advice and managed accounts because they help participants make smart investment decisions with minimal effort or expertise,” said Pam Hess, director of retirement research at Hewitt. “These features can really pay off for participants, [resulting in] thousands of dollars in additional retirement savings over time.”

Hewitt said that 50% of companies now offer some type of 401(k) investment advice, compared with just 17% in 2000.