Target-Date Funds: The Set-It-and-Forget-It Retirement Investment

Target-date funds have become the default investment option in millions of 401k plans and are increasingly the single investment recommendation for people who want to invest for retirement without spending significant time managing their portfolio. The concept is elegant: choose a fund with the year closest to your expected retirement, invest regularly, and let the fund automatically manage the allocation.

Despite their simplicity, or perhaps because of it, target-date funds are often underappreciated or misunderstood. Some investors see them as overly simplistic and switch to more complex self-managed portfolios that do not serve them better. Others hold them alongside many other funds, defeating their purpose. And some investors choose the wrong target date or do not understand what the fund's glide path means for their retirement.

This guide explains how target-date funds work, how to evaluate their quality, when they are the ideal choice, and when a different approach might be more appropriate.

How Target-Date Funds Work

A target-date fund is a fund of funds that holds a diversified mix of stocks, bonds, and sometimes other assets. Its defining feature is the glide path: the automatic shift from a higher equity allocation in the early years to a more conservative allocation as the target date approaches. A 2055 target-date fund might hold 90 percent stocks and 10 percent bonds today; by 2055, it might hold 50 percent stocks and 50 percent bonds.

Most fund families offer target-date series at five-year intervals: 2035, 2040, 2045, 2050, 2055, 2060, 2065. You choose the fund with the date closest to your expected retirement year. The fund does the rest, rebalancing automatically and shifting the glide path without any action required from the investor.

The through retirement concept is important: some target-date funds reach their most conservative allocation at the target date (to date); others continue to adjust toward a more conservative allocation for 10 to 20 years after the target date (through date). The through funds typically maintain higher equity allocations at retirement, based on research that suggests retirees need continued growth to fund long retirements.

The Quality Difference Between Target-Date Funds

Not all target-date funds are created equal, and the differences in expense ratios are particularly significant over a long investment horizon. A target-date fund charging 0.08 percent annually will produce significantly better long-term results than one charging 0.75 percent for a virtually identical portfolio, because the fee difference compounds continuously against performance.

Index-based target-date funds, which hold low-cost index funds as their underlying holdings, are consistently recommended over actively managed target-date funds because of this fee advantage. Vanguard, Fidelity Freedom Index, and Schwab Target Date Index funds are examples of index-based options that consistently outperform actively managed alternatives after fees.

The glide path design also matters. A fund that reaches an extremely conservative allocation (30 percent stocks) at the target date may leave retirees underexposed to the growth needed to fund a 25 to 30 year retirement. Research suggests that maintaining 40 to 60 percent equity at retirement and beyond provides better long-term outcomes for typical retirees.

When Target-Date Funds Are the Best Option

Target-date funds are the ideal choice for investors who want a complete, professionally managed portfolio in a single fund without active management on their part. They are specifically designed for 401k investors who do not want to actively manage their investments and are well-suited for the majority of retirement savers.

The behavioral advantage of target-date funds should not be underestimated. Investors who hold a single diversified target-date fund are far less likely to make reactive investment decisions during market downturns than those who manage a multi-fund portfolio and must make rebalancing decisions. The automatic rebalancing within the target-date fund removes this decision point entirely.

For investors in 401ks with high-fee actively managed funds as the only alternatives to a target-date fund, the target-date fund is almost certainly the best option available, providing instant diversification at the fund's total cost regardless of the quality of the other options.

When to Consider Alternatives to Target-Date Funds

Sophisticated investors who understand asset allocation and are committed to maintaining their own diversified portfolio may prefer a custom three-fund or four-fund portfolio to a target-date fund. This approach allows more control over the exact asset allocation, the specific index funds used (potentially at lower cost), and the tax location of different assets across taxable and tax-advantaged accounts.

High earners with multiple account types (Roth IRA, traditional IRA, taxable brokerage, and 401k) may find that holding assets across accounts tax-efficiently requires more customization than a target-date fund allows. Holding all bonds in tax-deferred accounts and all equities in taxable and Roth accounts requires individual fund selection rather than a target-date fund.

Investors who are significantly above or below the average risk tolerance for their target date may want to adjust by choosing a more aggressive or more conservative fund. A 40-year-old with very high risk tolerance might prefer a 2060 or 2065 fund to a 2045 fund for higher equity allocation. A 40-year-old planning early retirement at 55 might prefer a 2040 fund.

Final Thoughts

Target-date funds are the most appropriate retirement investment for most people in most 401ks. They provide instant diversification, automatic rebalancing, and age-appropriate allocation management in a single fund at reasonable cost when the fund family is a quality index-based provider.

The most important decision is the quality of the fund: choose index-based target-date funds with expense ratios below 0.15 percent rather than actively managed equivalents that charge five to ten times more for no demonstrated superior outcome. Within a quality fund family, hold the target-date fund as your single 401k investment and focus your energy on contributions rather than fund selection.

Simple works. A single low-cost target-date fund held consistently over decades outperforms the vast majority of more complex investment strategies in 401k accounts.