Hidden Fees in a 401(k): What Most Employees Never See

The Three Layers of 401(k) Fees

Every 401(k) plan carries costs that can be grouped into three categories. The total of all three determines what each participant actually pays.

Layer 1: Plan Administration and Record-Keeping Fees. These cover the cost of running the plan — maintaining participant accounts, processing contributions and distributions, providing the website and phone support, compliance testing, Form 5500 filing, and regulatory administration. These costs are either paid by the employer directly, charged to the plan as a whole (reducing all participants' returns proportionally), or assessed as a flat per-participant charge (such as $30 to $75 per person per year). In smaller plans, administration fees consume a larger percentage of assets because they are spread over fewer accounts.

Layer 2: Investment Management Fees (Fund Expense Ratios). This is typically the largest component of total plan cost. Every fund on the plan menu has an expense ratio — the same ongoing annual charge discussed in the context of mutual funds. The fund mix varies by plan. Some plans offer ultra-low-cost index funds with expense ratios of 0.02% to 0.05%. Others offer only actively managed funds with expense ratios of 0.60% to 1.20% or higher. The plan sponsor (usually the employer) selects the fund menu, and participants can only choose from what is offered.

Layer 3: Individual Service Fees. These are charged to specific participants for specific actions — such as taking a loan from the plan ($50 to $100 loan origination fee), processing a hardship withdrawal, or completing a qualified domestic relations order (QDRO). These fees are disclosed in the plan's fee disclosure notice and apply only to participants who use the service.

Revenue Sharing: The Hidden Subsidy

Revenue sharing is arguably the most misunderstood fee mechanism in 401(k) plans. It works like this: a mutual fund company agrees to pay a portion of its expense ratio back to the plan's record-keeper or third-party administrator. This payment, typically 0.10% to 0.35% of fund assets, subsidizes the record-keeper's fees and reduces or eliminates the explicit administration charges the employer would otherwise pay.

On the surface, this arrangement appears to benefit everyone — the employer pays less for plan administration, and participants do not see a separate administrative fee. But the cost is not eliminated; it is hidden inside higher fund expense ratios. A plan using revenue sharing might offer funds with expense ratios of 0.70% to 0.90%, of which 0.25% flows back to the record-keeper. The same funds in a non-revenue-sharing plan might cost 0.45% to 0.65%, with the employer paying administration fees separately.

The net effect is that participants in revenue-sharing plans often pay more in total because the fund expense ratios are inflated to cover administrative costs that should arguably be the employer's responsibility. Revenue sharing also creates an incentive for plan administrators to include higher-cost funds on the plan menu, since those funds generate more revenue-sharing payments.

How to Read a 408(b)(2) Fee Disclosure

The Department of Labor requires every 401(k) service provider to deliver a fee disclosure document — known as a 408(b)(2) disclosure — to the plan fiduciary (typically the employer or plan committee). This document must detail all direct and indirect compensation the provider receives from the plan.

While employees do not automatically receive the 408(b)(2) document, they are entitled to request it from their employer or HR department. When reviewing it, look for:

1. Total record-keeping compensation: What the record-keeper receives from all sources — direct fees from the plan, revenue sharing from funds, and any other indirect compensation.
2. Revenue sharing amounts by fund: How much each fund on the plan menu pays back to the record-keeper. This reveals which funds carry inflated expense ratios to support revenue sharing.
3. Investment advisory fees: If the plan uses an investment advisor to select and monitor funds, what fee does the advisor charge? This is separate from fund expense ratios.
4. Per-participant charges: Any flat fees assessed to each participant's account for record-keeping or administration.

In addition to the 408(b)(2), participants receive an annual fee disclosure notice (required under ERISA Section 404a-5) that shows the expense ratio of each investment option and any plan-level fees charged to their account. This document typically arrives in Q1 of each year and provides the most accessible summary of what a participant is actually paying.

Small Plans Pay More: The Scale Problem

Plan size has an enormous impact on total fees. A large plan with $100 million in assets and 5,000 participants can negotiate institutional-class fund pricing (expense ratios of 0.02% to 0.10%) and spread administration costs over a large asset base, resulting in total plan costs of 0.30% to 0.50%.

A small plan with $2 million in assets and 25 participants faces a fundamentally different cost structure. The same administrative services — compliance testing, Form 5500, participant statements, website — cost roughly the same regardless of plan size. With fewer assets to absorb those costs, the effective fee percentage is much higher. Small plans commonly see total costs of 1.50% to 2.50% of assets.

This scale problem is one reason many small-business owners have been slow to offer 401(k) plans — the per-participant cost can feel disproportionate. Newer platforms such as pooled employer plans (PEPs) and multiple employer plans (MEPs) aim to address this by aggregating small plans together to achieve scale and lower costs.

What Employees Can Do

Although individual employees cannot unilaterally change their 401(k) plan's fee structure, they can take several meaningful steps:

1. Request the plan's fee disclosure documents — both the annual 404a-5 participant notice and the 408(b)(2) provider disclosure. HR departments are required to provide these upon request.
2. Identify the lowest-cost funds on the plan menu and allocate to those options where appropriate. Index funds and target-date funds with expense ratios below 0.10% are the most cost-effective choices in most plans.
3. Calculate total plan cost by adding the plan administration fee (if charged per participant) to the weighted-average expense ratio of your chosen funds.
4. Benchmark against peers. The BrightScope database and the Department of Labor's Form 5500 filings provide fee data on thousands of 401(k) plans. If your plan's total cost exceeds 1.00% for a plan of similar size, it may be worth raising the issue with the plan committee.
5. Advocate for a plan review. Employers have a fiduciary obligation under ERISA to ensure plan fees are reasonable. Presenting data on competitive fee benchmarks can prompt a review that benefits every participant in the plan.