NEW YORK (MainStreet) — It seems the big companies always have the best benefits. Better insurance, country club memberships, free lunches and snacks – even nap pods. But when it comes to the biggest benefit of all, a company-sponsored retirement plan, the little guys are bringing home the bacon.

In an analysis of 401(k) plan disclosure documents released by the Department of Labor, Judy Diamond Associates, a data provider to financial services firms, scored the performance of retirement plans of large companies versus small. Bottom line: the smallest plans outperform the largest.

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Employer-sponsored plans at companies with 100 or more participants had an average plan score of 52.3 out of 100. Very small plans – defined as having ten or fewer participants – scored 63.8 over the same period.

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The ratings were calculated using an algorithm considering key measures of a plan's performance compared to other plans nationwide. "Higher plan scores can result from comparatively higher participation rates, increases in contributions, higher rates of return, or an absence of certain signs of distress," the report says.

"This research underscores the needs for advisors who work with the largest 401(k) plans to continue to look for ways to improve their performance," said Eric Ryles, managing director of Judy Diamond Associates. "By increasing automatic enrollment, restructuring their company match, and increasing participant education, a small portion of large plan sponsors can have a huge impact on the way we save for retirement."

The outperformance of such small plans is a benefit limited to an exclusive group of participants: under 2% of all 401(k) participants are enrolled in such "micro" plans. Most American workers (73.4%) are participating in the largest plans offered, in companies with workforces numbering in the hundreds or thousands.

Regardless of size, two of the top three industries offering 401(k) plans are health care and finance. Other scores for varying sizes of 401(k) plans were:

  • Giant (500+ participants) 52.3
  • Large (101-500) 52.3
  • Medium (51-100) 53.3
  • Small (11-50) 57.1
  • Micro (1-10) 63.8

Previous research by Diamond revealed that – unsurprisingly – finance and insurance professionals have the highest ranked 401(k) plans out of 20 industry classifications analyzed. Accommodation and food services workers had the lowest-rated company retirement plans.

--Written by Hal M. Bundrick

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