In July 2012, a seemingly technical regulation from the Department of Labor took effect. It required 401(k) service providers to disclose every dollar they earned from a plan, including indirect payments like revenue sharing from mutual funds. The goal was straightforward: let plan sponsors and participants see the true cost of their retirement accounts. What followed was not a wave of cost reductions but a quiet, industry-wide repricing that added roughly three percent to annual plan costs.

The Rule That Quietly Reshaped 401(k) Costs

The regulatory push began in 2009, when the Department of Labor proposed a set of rules aimed at making 401(k) fees visible. At the time, a typical participant might receive a quarterly statement showing a balance and a vague line for "administrative fees," if that. Hidden inside mutual fund expense ratios were 12b-1 fees, sub-transfer agency fees, and other charges that never appeared as a separate line item. The final rule, known as 408(b)(2), became effective on July 1, 2012. It required every service provider—recordkeepers, investment advisors, broker-dealers—to deliver a written disclosure of all compensation, direct and indirect, to the plan sponsor.

Before 408(b)(2), many plan sponsors did not know how much they were paying. A 2010 survey by Deloitte found that roughly 40 percent of sponsors could not identify the total fees their plan incurred. The rule forced them to look. Service providers suddenly had to itemize revenue-sharing payments, which often accounted for a large share of their income. For sponsors, the new information was eye-opening, but it also created a new problem: now that they knew the costs, they had a fiduciary duty to evaluate whether those costs were reasonable.

The immediate effect was a flurry of fee benchmarking. Sponsors hired consultants to compare their plan's expenses against peers. Many discovered that their plan's total expense ratio—the sum of all investment management and administrative fees as a percentage of assets—was somewhere around 0.5 percent. But that number often excluded revenue-sharing credits that reduced the sponsor's out-of-pocket costs. When those credits were factored in, the true cost was higher. The rule did not mandate a change in fee structures, but it set off a chain reaction that would ultimately raise the headline number participants saw.

How a Three Percent Cost Increase Emerged from Disclosure

In the years following the rule, several studies tracked the trajectory of 401(k) fees. One widely cited analysis by Aon Hewitt examined plans with more than $1 billion in assets and found that the average total plan cost rose from roughly 0.5 percent of assets in 2012 to about 0.8 percent by 2015. That three-basis-point increase—three percent of the original cost—was not a result of providers raising prices. It was a consequence of how costs were now classified and charged.

Before the rule, many plans operated under a bundled model. A single provider handled recordkeeping, administration, and investment management, and the fees were buried inside the mutual fund expense ratios. Revenue-sharing payments from fund companies to the recordkeeper were netted against the sponsor's bill, so the participant never saw them. After the rule, sponsors began unbundling these services. They demanded separate line items for recordkeeping, advisory fees, and plan administration. The result was that participants started seeing explicit charges on their statements—per-participant fees of, say, $30 per quarter—that had previously been invisible.

The shift from hidden to explicit fees did not change the total amount flowing out of the plan, but it changed the reported expense ratio. When revenue-sharing credits were eliminated and replaced with direct charges, the expense ratio of the underlying investments often dropped. However, the new administrative fees added back to the total. In many cases, the net effect was a higher all-in cost. A 2014 study from the Investment Company Institute found that the average expense ratio for 401(k) participants actually fell slightly after the rule, but that was because the study excluded the new explicit administrative fees. When those were included, the trend reversed.

Some plans added recordkeeping surcharges that had not existed before. A small plan with 50 participants might have paid 0.75 percent in bundled fees before 2012. After the rule, the same plan might show a 0.60 percent investment expense ratio plus a $25 per-participant quarterly fee, which for a $50,000 account equates to 0.20 percent annually, bringing the total to 0.80 percent. The increase was not uniform, but the direction was clear: disclosure made costs more visible and, in many cases, higher.

Revenue Sharing: The Mechanism Behind the Rise

To understand why a transparency rule increased costs, one must understand revenue sharing. Mutual funds often pay fees to the firms that sell and administer them. The most common form is the 12b-1 fee, named after the SEC rule that permits it. These fees, typically 0.25 to 1.00 percent of assets annually, are deducted from the fund's returns and paid to broker-dealers and recordkeepers. In a 401(k) plan, the recordkeeper might receive a sub-transfer agency fee—another bundled payment—for maintaining participant accounts and providing statements.

Before 408(b)(2), these payments were opaque. The plan sponsor might receive a single bill from the recordkeeper that was net of revenue-sharing credits. The sponsor paid less out of pocket, but the participant's fund returns were reduced by the hidden fees. After the rule, sponsors could no longer accept undisclosed compensation. Many responded by demanding that revenue-sharing be eliminated and replaced with explicit fees. This unbundling had an unintended consequence: the explicit fees were often higher than the revenue-sharing payments they replaced.

Why? Because revenue-sharing was based on assets, and in a rising market, the dollar amount grew automatically. Recordkeepers liked that. When forced to charge a flat per-participant fee or a fixed percentage, they often set the price at a level that covered their costs plus a margin. For plans with large average balances, the new explicit fee might be lower than the old revenue-sharing. But for plans with small balances—typical of many small businesses—the per-participant fee ate a larger share of assets. The result was that total plan costs rose, especially for smaller plans.

The shift also changed incentives. Under the old model, recordkeepers had an incentive to keep assets in higher-fee funds because those generated more revenue sharing. After unbundling, that incentive weakened. Some sponsors moved to lower-cost index funds, which reduced investment expenses. But the administrative fees remained, and in many cases, they increased. The net effect was that participants saw a higher total cost on their statements, even as the underlying fund expenses fell. The three percent increase was, in part, a price for transparency.

Plan Sponsors Under Pressure to Justify Every Fee

The 408(b)(2) rule did not just change fee structures; it changed the fiduciary landscape. Under ERISA, plan sponsors are fiduciaries who must act prudently and solely in the interest of participants. Once they received the new disclosures, they had a duty to evaluate whether each fee was reasonable. This created a cottage industry of fee consultants and benchmarking reports. Sponsors who had never questioned their provider's pricing now had to document their review process.

Lawsuits followed. Beginning around 2013, a wave of class-action ERISA lawsuits targeted large plans for charging excessive fees. Plaintiffs' lawyers used the new disclosures to argue that sponsors had failed to monitor costs. Some high-profile cases settled for millions of dollars. The threat of litigation pushed sponsors to be more aggressive in fee negotiations. Many hired third-party fiduciaries to take over the responsibility. The cost of those consultants, of course, was passed back to the plan.

Smaller sponsors felt the pressure most acutely. A plan with $5 million in assets might pay 1.5 percent in total fees, while a plan with $500 million might pay 0.5 percent. The rule did not mandate fee levels, but it made the disparity visible. Some small plans consolidated into multiple-employer plans or pooled employer plans to gain negotiating leverage. Others simply accepted the higher costs as a cost of compliance. The annual benchmarking ritual became standard, but it did not always lead to lower fees.

The fiduciary pressure also accelerated a shift toward target-date funds. These funds offered a simple, one-decision solution for participants, and they came with a single expense ratio that bundled investment and administrative costs. Sponsors liked them because they reduced the need to monitor multiple funds and because the fees were transparent. By 2016, target-date funds held roughly 25 percent of 401(k) assets, up from 15 percent in 2010. The rule did not cause this shift, but it made it easier for sponsors to justify a single, disclosed fee.

The Participant's Statement: What Changed on Paper

For participants, the most visible change came with a companion rule: the participant-level fee disclosure, effective in 2013. Under this rule, plan administrators must provide each participant with a quarterly statement showing the dollar amount of fees deducted from their account. For the first time, a participant could see that $15.75 had been taken out for administrative costs, rather than just a percentage buried in a prospectus. The idea was that transparency would spur participants to demand lower fees or switch to cheaper investments.

In practice, the effect was muted. A 2015 Government Accountability Office (GAO) report found that only 12 percent of participants reviewed the fee disclosures in detail, and fewer than 5 percent took any action as a result. Most participants did not notice the new disclosures or did not understand them. The quarterly statements showed fees in dollar terms, but without context—was $15.75 high? Low? Average?—participants had little basis for action. Some participants mistakenly thought the new line item was an additional charge, not a repackaging of existing costs. Confusion was common.

Behavioral change was limited. A few participants moved to lower-cost index funds, but most stayed put. The inertia that characterizes retirement saving persisted. For participants in plans with automatic enrollment, the default investment option—often a target-date fund—had a disclosed fee that was now explicit. But because they were defaulted in, they rarely evaluated alternatives. The transparency rule gave participants information without making it actionable.

There were exceptions. Some large employers used the new disclosures to educate employees, hosting webinars and sending comparison charts. In those cases, participants did shift assets toward lower-cost options. But for the majority of plans, especially those with fewer than 100 participants, the quarterly statement became just another piece of paper. The rule succeeded in making fees visible, but it did not succeed in making them lower.

Three Percent as a Ceiling: The Long-Term Impact

By 2015, the initial shock of the disclosure rule had settled. Total plan costs stabilized in a range of roughly 1.0 to 1.5 percent of assets for the average plan, down from the pre-disclosure hidden costs that some estimates put near 1.8 percent for small plans. The three percent increase in explicit costs was, in many cases, a one-time adjustment. After that, competition among providers began to push fees down again, especially for large plans.

Large plans with billions in assets negotiated aggressively. They demanded and got lower recordkeeping fees, often below $10 per participant per year. They shifted to institutional share classes of mutual funds with expense ratios under 0.10 percent. By 2020, a large plan could have a total cost below 0.3 percent. But small plans, those with under $10 million in assets, continued to pay 1.5 percent or more. The disclosure rule did not close the gap between large and small plans; it made it visible.

The rise of index funds and exchange-traded funds also played a role. As participants and sponsors became more cost-conscious, they gravitated toward low-cost options. The average expense ratio for equity mutual funds in 401(k) plans fell from 0.62 percent in 2012 to 0.45 percent in 2018, according to the Investment Company Institute. But that decline was offset by the new explicit administrative fees. The net effect was that the all-in cost for the median participant stayed roughly flat after the initial jump.

The three percent increase, then, was a ceiling, not a floor. It represented the maximum additional cost that the disclosure rule imposed, and it was temporary. Over time, the transparency that the rule created allowed market forces to work. But the process was slow, and it came at a cost. For participants in the years immediately following the rule, the net effect was a higher bill. The trade-off was that they now knew what they were paying for.

What the Next Fee Disclosure Rule Should Address

The 408(b)(2) rule was a landmark, but it left gaps. One major gap is brokerage windows—self-directed accounts within a 401(k) that allow participants to buy individual stocks and bonds. These windows often carry hidden fees, including trading commissions and markups on fixed-income securities, that are not disclosed under the current rules. A participant who uses a brokerage window may pay far more than the plan's standard fees without knowing it. For example, a participant buying a corporate bond through a brokerage window might pay a markup of 1-2 percent of the bond's value, a cost that never appears on the quarterly statement. Similarly, trading commissions for frequent stock trades can add up to hundreds of dollars per year, yet the participant sees only the net trade amount. A 2018 study by the Government Accountability Office found that brokerage window fees in 401(k) plans varied widely and were often not disclosed in a standardized way, making it difficult for participants to compare costs. The Department of Labor has considered extending disclosure requirements to brokerage windows, but as of mid-2026, no rule has been finalized.

Another gap is annuity and insurance products. Many 401(k) plans offer guaranteed income options, such as fixed annuities, that have opaque fee structures. The mortality and expense charges, administrative loads, and surrender fees are often buried in the contract. For instance, a fixed annuity might carry a mortality and expense risk charge of 1.25 percent annually, an administrative fee of $30 per year, and a surrender charge of 7 percent if the participant withdraws funds within the first seven years. None of these costs would appear on the participant's quarterly statement under current rules. The Department of Labor has proposed expanding disclosure requirements to these products, but as of mid-2026, the rule has not been finalized. The SEC's Regulation Best Interest, which applies to broker-dealers, overlaps in some areas but does not cover all annuity sales within retirement plans.

A proposed DOL fiduciary rule, first introduced in 2023, would expand the definition of fiduciary advice to include rollover recommendations and one-time advice. If finalized, it would require advisors to disclose conflicts of interest and fees in a more standardized way. But the rule has faced industry pushback and may not survive in its current form. The political landscape makes the outcome uncertain.

What participants really need is a lifetime cost projection. A single number that shows how much fees will reduce their account balance at retirement, in today's dollars, given their current savings rate. Some plan providers already offer such calculators, but they are not mandatory. The next rule should require a standardized projection on every annual statement. Until then, the legacy of 408(b)(2) is a mixed one: more transparency, but not necessarily lower costs, and not always better outcomes.

This article is for informational purposes only and does not constitute personalized investment or legal advice. Consult a qualified professional for advice tailored to your specific situation.