Retirement Plan Types Compared: 401(k), Pension, ESOP, and More

Not all retirement plans are created equal. This comparison uses DOL Form 5500 data to show how each plan type works, who offers them, and what the data reveals about their prevalence and funding.

Key Findings

  • 1.401(k) plans dominate by count and participants, but defined benefit plans still hold a significant share of total assets, reflecting legacy plans with decades of accumulated wealth.
  • 2.ESOPs represent a small fraction of total plans but have outsized average assets per plan, reflecting their concentration among mid-to-large employers committed to employee ownership.
  • 3.The shift from defined benefit to defined contribution plans is visible in the data, new DB plans are extremely rare, while 401(k) plan formation continues to grow.
  • 4.Profit sharing plans often coexist with 401(k) plans, as many 401(k)s include a profit-sharing component for employer contributions.

401(k) Plans: The Dominant Type

401(k) plans are defined contribution plans where employees defer a portion of their salary into an individual account and choose from a menu of investment options. The employer may or may not match contributions. Investment risk falls entirely on the employee, there is no guaranteed retirement income. They are by far the most common type of employer-sponsored retirement plan in the US today.

Form 5500 data reveals enormous variation within the 401(k) category. Some plans have millions of participants and billions in assets; others serve 10 employees with $100,000 total. Browse 401(k) plans on PlainRetire to see the full distribution.

Defined Benefit Pensions: The Legacy Plans

Defined benefit plans promise a specific monthly payment in retirement, typically based on salary and years of service. The employer bears the investment risk and must fund the plan sufficiently to meet its obligations. Once the backbone of American retirement, DB plans are now increasingly rare in the private sector, most new plans are 401(k)s.

However, Form 5500 data shows that remaining DB plans still hold enormous assets. Many large corporations maintain frozen DB plans that no longer accept new participants but continue to pay benefits and manage investments. Explore defined benefit plans on PlainRetire.

ESOPs, Profit Sharing, and Money Purchase Plans

Employee Stock Ownership Plans invest primarily in the sponsoring company's stock, aligning employee and company interests. They receive special tax treatment and are used by many mid-size companies as a succession planning tool. Profit sharing plans allow employers to make discretionary contributions based on company profitability. Money purchase plans require fixed annual employer contributions as a percentage of pay.

Each type appears in Form 5500 data with distinct characteristics. ESOPs tend to have high per-plan assets, profit sharing plans are often combined with 401(k)s, and money purchase plans are relatively uncommon today.

Explore by Type

Data source: DOL EBSA, Form 5500 Datasets (2024).

Analysis published: April 2026