A 401(k) statement is designed to show a balance and a rate of return, not to make fees obvious. That is not necessarily deliberate obfuscation — it is just how the disclosure requirements evolved — but the practical result is that most participants have never looked closely at what they are paying, and the gap between a low-fee plan and a high-fee plan can quietly cost tens of thousands of dollars over a career.
The Expense Ratio Is the One People Know About
Every mutual fund or index fund inside your 401(k) has an expense ratio, expressed as a percentage of assets charged annually. A fund with a 0.05 percent expense ratio costs $5 a year per $10,000 invested. A fund with a 0.75 percent expense ratio costs $75 a year on the same balance. That difference looks small in dollar terms on a modest balance, but it compounds against you every single year, and on a balance that grows into six figures over a career, the gap between those two expense ratios can total tens of thousands of dollars in fees paid versus growth kept.
This number is usually listed next to each fund option in your plan's investment menu, sometimes labeled "gross expense ratio" or simply "expenses." If your plan offers both an actively managed fund and a passive index fund tracking a similar market segment, compare the two directly — the index fund is very often the lower-cost option without a corresponding difference in long-term performance.
Plan Administration Fees Are the Ones People Miss
Separate from fund expense ratios, many 401(k) plans charge a recordkeeping or administrative fee to cover the cost of running the plan itself — statements, the online portal, compliance testing, and customer service. Depending on the plan, this might be paid by the employer, charged as a flat dollar amount to each participant, or charged as a percentage of assets. When it is charged to participants, it typically shows up in a separate fee disclosure document rather than on the monthly or quarterly statement, which is exactly why it goes unnoticed.
Federal law requires plans to provide this disclosure at least annually, often called a "404(a)(5) notice." It is usually a dense document, but the relevant section lists administrative fees and any per-transaction charges, such as fees for taking a loan against the plan. If you cannot find yours, your plan administrator or HR department can provide it on request, and it costs nothing to ask.
Why This Matters More the Longer You Stay
Fee impact compounds with time, which means it matters most for the money you contribute earliest in your career, not latest. A dollar contributed at 25 has decades for a fee drag to compound against it; a dollar contributed at 60 has very little time for the same drag to matter. This is part of why reviewing fees is worth doing early rather than treating it as a pre-retirement task — the earliest contributions are the ones with the most at stake.
What to Do If Your Plan's Fees Look High
If your employer's 401(k) options are genuinely expensive across the board, you still generally want to contribute at least enough to capture the full employer match, since the match itself is an immediate return that outweighs almost any fee drag. Beyond the match, some people choose to direct additional retirement savings to an IRA with a wider selection of low-cost funds, then return to the 401(k) for anything above the IRA contribution limit. This is a reasonable way to balance fee minimization with using all the tax-advantaged space available to you.
If you are comparing a Roth versus traditional IRA as that overflow account, fee structure is a separate decision from tax treatment, and most major brokerages now offer IRA share classes of the same funds at lower cost than what many employer plans provide. The Department of Labor publishes a plain-language guide to understanding 401(k) fees at dol.gov, including a worksheet for comparing your plan's disclosed fees against typical benchmarks for plans of a similar size.