Somewhere inside your 401(k) account, a number you have probably never looked at is shaving money off your retirement balance every single day. It is called an expense ratio, and it works silently: no line-item debit, no notification, no receipt. The fee is baked into the price of the mutual fund or target-date fund your money sits in, deducted from the fund’s assets before returns ever reach your statement.
Three separate investigations by the Government Accountability Office, published between 2006 and 2021 (GAO-07-21, GAO-09-641, GAO-21-357), found that most 401(k) participants either did not understand the fee disclosures they received or never reviewed them at all. As of June 2026, no subsequent federal survey has shown that pattern has meaningfully changed.
That gap in awareness matters more than most people realize, because the difference between a cheap fund and an expensive one, compounded over a full career, can erase six figures from a retirement balance.
How a “small” fee becomes a six-figure loss
Run a simple scenario. A 25-year-old worker contributes $6,000 a year to a 401(k) and earns a 7% average annual return before fees. By age 65, that account would grow to roughly $1.2 million if invested in a broad-market index fund charging 0.04% per year, a rate now common from providers like Vanguard and Fidelity.
Switch to a fund charging 1.00% annually, a level that still exists in many small-business plans, and the balance drops to about $998,000. The gap: approximately $200,000, all consumed by that seemingly negligible percentage.
The Securities and Exchange Commission has published its own version of this warning. Its investor bulletin on mutual fund fees explains that expense ratios reduce returns before they ever appear on a statement. A companion SEC alert on portfolio costs adds that the stated expense ratio may not capture every charge: trading spreads, account-level administrative fees, and revenue-sharing arrangements can push the all-in cost higher still.
In other words, the number on the label may actually understate what you are paying.
Why the fee is so easy to miss
Credit cards show every transaction. Bank accounts list every monthly maintenance charge. But a 401(k) expense ratio never appears as a debit. It is embedded in the fund’s daily net asset value, which means the cost is invisible unless you actively go looking for it.
Federal regulators recognized this problem more than a decade ago. In 2012, the Department of Labor’s Employee Benefits Security Administration began requiring plan administrators to furnish participants with standardized fee disclosures at least once a year, under a regulation known as 29 CFR 2550.404a-5. Those documents must list each investment option’s expense ratio, any administrative charges, and the total annual cost expressed as both a percentage and a dollar amount per $1,000 invested. The Labor Department also published a plain-language guide to 401(k) fees aimed at helping non-experts interpret the numbers.
The disclosures exist. The problem is that almost nobody reads them. The GAO’s most recent report, published in 2021, found that participants told auditors the documents were confusing, too long, or easy to ignore alongside the other mail and email they received from their plans. The auditors recommended that the Labor Department do more to help participants actually use the information, not just receive it.
What a typical 401(k) charges right now
Fees have dropped significantly over the past two decades, but the average still masks a wide range. The Investment Company Institute, the fund industry’s trade group, reported in its 2024 annual survey that the asset-weighted average expense ratio for equity mutual funds held in 401(k) plans fell to 0.36% in 2023, down from 0.72% in 2000. That decline reflects a massive shift toward index funds and institutional share classes, driven partly by employer awareness and partly by a wave of excessive-fee lawsuits under the Employee Retirement Income Security Act (ERISA).
But where you work can determine what you pay. Employees at large corporations with billions in plan assets often have access to institutional share classes charging 0.01% to 0.10%. Workers at small businesses may be offered retail share classes of the same fund at 0.50% to 1.00% or higher, because smaller plans lack the bargaining power to negotiate institutional pricing. The GAO flagged this disparity years ago, and regulation alone has not closed it.
Target-date funds add another wrinkle. These age-based portfolios are now the default investment in most 401(k) plans, a shift enabled by the Pension Protection Act of 2006. Some target-date series charge under 0.10%; others, particularly those built from actively managed underlying funds, charge 0.50% or more. Because many participants are auto-enrolled into a target-date fund and never revisit the choice, the cost of that default can follow them for their entire career.
How to check your fees in about 10 minutes
Start with the annual fee disclosure your plan is required to send, sometimes labeled a “404a-5 notice” after the regulation that mandates it. It lists every fund in your plan alongside its expense ratio and any per-participant administrative charges.
If you cannot find that document, log into your plan’s website. Most major recordkeepers, including Fidelity, Vanguard, Empower, TIAA, and Schwab, display each fund’s expense ratio on the investment-options page. Look for a column labeled “Exp. Ratio” or “Gross/Net Expense Ratio.”
Once you have the number, compare it to a benchmark:
- Broad U.S. stock index fund: Anything above 0.10% in a workplace plan is worth questioning.
- Target-date fund: The ICI data puts the asset-weighted average at 0.26% in 2023. If yours is significantly higher, ask your HR department or plan administrator why.
Under ERISA, your employer has a fiduciary duty to monitor plan fees and ensure they are reasonable for the services provided. That does not mean every plan must offer the cheapest fund on the market, but it does mean your employer should be able to explain why a higher-cost option was selected over a lower-cost alternative. If you believe your plan’s fees are unreasonable, you can file a complaint with the Department of Labor’s Employee Benefits Security Administration.
One more option worth knowing: some plans allow “in-service rollovers,” which let you move a portion of your balance into an IRA while still employed. An IRA gives you access to the full universe of low-cost funds. Not every plan permits this, but it is worth asking your plan administrator.
The questions regulators still have not answered
Despite more than a decade of disclosure rules, several important gaps remain. No publicly available post-2021 federal data confirms whether the share of participants who actually review their fee disclosures has increased. The GAO documented the problem repeatedly but has not published a follow-up measuring whether its own recommendations moved the needle.
There is also no single federal tool that lets a worker type in an employer’s name and see a ranked comparison of fund costs within that specific plan. The Labor Department collects annual Form 5500 filings from plan sponsors, and the SEC’s EDGAR database houses fund-level expense data, but neither system is designed for easy consumer comparison shopping. Third-party tools like BrightScope (now owned by ISS) offer some plan-level ratings, but they are not government-run and may not cover every plan.
How fee awareness breaks down by income, industry, and plan size is another gap. Workers with outside financial advisers may be more likely to scrutinize costs, while lower-wage employees who rely solely on plan materials may not. The available federal record does not resolve that question with current data.
What the record does establish, clearly and repeatedly, is the arithmetic: fees compound just as returns do, and a percentage point that looks negligible in any single year can quietly consume a substantial share of a retirement balance over 30 or 40 years. The six-figure cost in the headline is not a scare tactic. It is a straightforward projection that the SEC, the GAO, and the Department of Labor have all, in their own ways, confirmed.
The 10-minute task most retirement savers have skipped
Checking your 401(k) expense ratios will not make you rich overnight. But the federal evidence accumulated over nearly two decades points to a consistent conclusion: most savers are paying fees they have never examined, on money they cannot afford to lose, inside accounts they will not touch for years or decades.
Compounding works in both directions. Low fees let more of your returns stay invested, building on themselves year after year. High fees do the opposite, siphoning off growth so gradually that you never feel the loss until you see the final number. The only step that separates those two outcomes is the one most people have not yet taken: pulling up your account, finding the expense ratio column, and reading it.
