45.4% of Boomer Investors on Fidelity Put Their 401(k) Entirely in One Target-Date Fund. What It Holds at Age 67

Nearly half of Boomers using Fidelity’s platform keep every dollar in a single target-date fund and never dig into what’s inside it. But the actual mix at retirement age depends on personal details the fund itself does not know.

This post may contain links from our sponsors and affiliates, and Flywheel Publishing may receive compensation for actions taken through them.

Target-date funds are the default option in most workplace retirement plans, and many older savers use one for their entire 401(k). According to Fidelity’s latest 401(k) data, 45.4% of Boomers have all of their 401(k) money in a target-date fund.

The figure is 54.9% for Gen X and 63.0% for savers overall. Many Boomers picked the fund labeled with their expected retirement year when they enrolled, then never looked inside again.

Related coverage has used the same Fidelity report to note the average Boomer 401(k) balance of $270,800 and to highlight savers in their 50s who remain fully invested in stocks. That makes it useful to look at what a target-date fund actually contains once its owner is at retirement age.

How a Target-Date Fund Works

A target-date fund is a single fund that holds a blend of stocks and bonds. The year in its name is meant to roughly match the year the investor expects to retire. Early on, it usually holds mostly stocks, which can grow more over long periods but also fluctuate more sharply.

As the target year approaches, the fund gradually shifts more money into bonds, which typically move less. That scheduled change over time is known as a glide path.

Fidelity uses a sample glide path to judge whether a saver’s investments fit their age. It begins with 90% stocks at age 25 and declines to 19% stocks 10 to 19 years after retirement.

Fidelity says older workers often joined their plans before automatic enrollment started placing new hires directly into target-date funds. More than 40% of workers in their 50s and early 60s choose their own investments.

What a 2025 Fund Holds Now

Someone who is 67 now likely retired around the target year of 2025, so a 2025 fund is the closest match. One of the largest 2025 funds reported holdings as of June 30, 2026. Roughly 48% was invested in U.S. and international stock index funds. About 51% was in bond funds, and a short-term inflation-protected bond fund accounted for about 8.6% of assets.

That allocation looks much like the way older savers are invested overall. Vanguard’s How America Saves 2025 found that participants age 65 and older had a median stock allocation of 50%. Vanguard’s 2026 edition found that 73% of target-date investors held only one target-date fund in 2025.

Funds That End at Retirement and Funds That Keep Evolving

Funds carrying the same year on the label can still have very different mixes when that year arrives. The Department of Labor advises participants that “it is important to know whether a target date fund’s glide path uses a ‘to retirement’ or a ‘through retirement’ approach.”

A “to” fund reaches its most conservative allocation at the target date and then stays there. A “through” fund continues shifting toward bonds for years after the target date, so it typically holds more stocks on the retirement date itself.

Why One Fund Can Suit One Retiree but Not Another

A target-date fund only knows the year in its name. It has no information about Social Security, a pension, a spouse’s 401(k), or savings held elsewhere, even though all of those affect how much risk a 401(k) can reasonably carry.

Consider two 67-year-olds in the same 2025 fund, using stated assumptions. The first depends on Social Security alone, at about the typical retiree benefit of $2,071 a month, and has no pension. That 401(k) has to cover everything else, including the standard Medicare Part B premium of $202.90 a month.

A steep stock decline would hit money needed for regular bills, so an almost even split could be more aggressive than this retiree can tolerate.

The second retiree receives the same Social Security check plus a pension that covers basic expenses. For this person, the 401(k) is extra money that may not be touched for a decade, so a fund with about half its assets in bonds could be more conservative than necessary.

The difference between the two cases comes down to the risk of a market drop early in retirement, which can do much more damage than one that arrives later.

Fees Matter More After Contributions Stop

Every target-date fund has an expense ratio, the annual fee charged as a percentage of assets. Those costs vary by fund family and by whether the series is index-based or actively managed.

In retirement, the fee is taken from a balance that is usually near its highest point, and no new contributions are coming in to offset it. A portfolio with more bonds also tends to earn less, so the same fee represents a larger share of the return. Each plan’s annual fee disclosure lists the expense ratio.

The Chart That Answers Most of the Questions

A fund’s glide path chart is usually found in the fact sheet or prospectus. It shows the stock allocation at each age and whether the fund stops changing at the target year or keeps moving. The 10-year Treasury yield stood at 5.05% on October 28, 2026, up from 4.11% a year earlier.

That shift affects the bond portion of these funds. Looking at the chart alongside Social Security, pension income, and outside savings helps show how the fund’s mix fits into the rest of a retiree’s income picture.