EBRI Issue Brief

What Does Consistent Participation in 401(k) Plans Generate? Changes in 401(k) Plan Account Balances, 2010–2018

Oct 1, 2020 19  pages


This paper provides an update of a longitudinal analysis of 401(k) plan participants drawn from the EBRI/ICI 401(k) database.

Because the annual cross sections cover participants with a wide range of participation experience in 401(k) plans, meaningful analysis of the potential for 401(k) participants to accumulate retirement assets must examine the 401(k) plan accounts of participants who maintained accounts over all of the years being studied (consistent participants). For example, because of changing samples of providers, plans, and participants, changes in account balances for the entire database are not a reliable measure of how individual participants have fared. A consistent sample is necessary to accurately gauge changes, such as growth in account balances, experienced by individual 401(k) plan participants over time.

A few key insights emerge from looking at the 1.9 million consistent participants in the EBRI/ICI 401(k) database over the eight-year period from year-end 2010 to year-end 2018.

  • The average 401(k) plan account balance for consistent participants rose each year from 2010 through year-end 2017 before edging down in 2018. Overall, the average account balance increased at a compound annual average growth rate of 13.9 percent from 2010 to 2018, rising from $63,756 to $180,251 at year-end 2018.
  • The median 401(k) plan account balance for consistent participants increased at a compound annual average growth rate of 17.3 percent over the period, to $90,015 at year-end 2018.
  • The growth in account balances for consistent participants generally exceeded the growth rate for all participants in the EBRI/ICI 401(k) database.

Younger 401(k) participants or those with smaller year-end 2010 balances experienced higher percent growth in account balances compared with older participants or those with larger year-end 2010 balances. Three primary factors affect account balances: contributions, investment returns, and withdrawal and loan activity. The percent change in average 401(k) plan account balance of participants in their twenties was heavily influenced by the relative size of their contributions to their account balances and increased at a compound average growth rate of 39.9 percent per year between year-end 2010 and year-end 2018.

401(k) participants tend to concentrate their accounts in equity securities. The asset allocation of the 1.9 million 401(k) plan participants in the consistent group was broadly similar to the asset allocation seen in the annual EBRI/ICI 401(k) database updates. On average at year-end 2018, about two-thirds of consistent 401(k) participants’ assets were invested in equities — through equity funds, the equity portion of target-date funds, the equity portion of non-target-date balanced funds, or company stock. Younger 401(k) participants tend to have higher concentrations in equities than older 401(k) participants.