What Should You Compare When Evaluating Your 401(k) Plan's Fees?
A 401(k) fee disclosure is often dense enough that most participants file it away unread, but a few specific comparisons can tell you most of what you need to know about whether a plan’s costs are reasonable.
The short answer
Evaluating a 401(k) plan’s fees generally comes down to three checks:
- Fund expense ratios. Compare each fund’s cost to the average for similar fund types, not just to other funds in the same lineup.
- Brokerage window costs. Look for extra fees tied to any self-directed or expanded-choice option, since these often sit outside the core lineup’s pricing.
- The annual fee notice. Read it to see exactly what’s charged, how, and to whom.
None of these require special expertise — they just require actually opening the documents most people skip.
Compare fund expense ratios to category averages
Every fund in a plan lineup lists an expense ratio, which reflects the investment management fee and related costs baked into that fund’s returns. The number alone doesn’t mean much without context — what matters is how it compares to similar funds of the same type. An index fund tracking a broad benchmark should generally cost less than an actively managed fund with a similar objective, so comparing within categories, rather than across very different fund types, gives a more honest read on whether a specific fund is priced competitively.
Check for brokerage window costs
Some plans offer a self-directed brokerage window that expands investment choices well beyond the core lineup. This flexibility often comes with its own separate costs — trading commissions, account fees, or access charges — that don’t show up in the core plan’s expense ratios at all. Someone using the window without checking its separate fee schedule can end up paying meaningfully more than the standard lineup would have cost, so it’s worth treating the window as its own cost category rather than assuming it’s covered by the plan’s general fee structure.
Reading the annual fee notice
Plans are generally required to send participants an annual notice describing plan-level fees, how they’re charged, and whether they’re deducted from accounts directly or covered by the employer. This notice is the most direct source for understanding what’s actually being paid, and it typically breaks out administrative costs separately from investment costs — useful context for spotting whether a plan uses a bundled wrap fee rather than itemized charges.
Why this matters beyond the plan itself
Fees compound the same way returns do: a small ongoing cost, deducted every year over a long enough period, adds up to a meaningfully larger reduction in an ending balance than the headline percentage suggests. This is also the same comparison work that plan sponsors are expected to do periodically, sometimes through a formal fee benchmarking review, so a participant doing this on their own account is essentially applying the same discipline expected at the plan level.
What to weigh
There’s no single “correct” fee level, since costs vary by plan size, provider, and the mix of services included. What matters is whether the fees look reasonable relative to comparable options and whether they’re clearly disclosed rather than buried in a bundled number. A little time spent reading the annual notice and comparing expense ratios within fund categories is usually enough to answer that question.