Article featured in Valuewalk. May 24, 2021. For most Americans, 401(k) plan accounts have become the predominant retirement savings vehicle.  Currently, more than $6.4 trillion is invested in 401(k) plans across the country, a 73% increase in the past ten years.1  An additional $2.7 trillion is invested in other defined-contribution plans, such as 403(b) plans for educational…