(Bloomberg) -- For years, fees on investments inworkplace retirement savings plans have beenfalling.

Now, at least for the moment, they’re stalling.

The average expense ratio on investments in defined contribution plans dropped by ahair to 0.41 percent of assets this year, according to thelatest annual survey from investment consulting firm NEPC.

That follows three straight years of somewhat deeperdeclines, spurred in large part by regulatorypressure and a rash of high-profile class action lawsuitsalleging excessive fees and plan designs that weren’t in savers’best interests.

The all-in cost of plans, including fees tied to investmentmanagement, record-keeping, and trust and custody services,have also been dropping in recent years.

In the latest survey, it flattened out at 0.43 percent, thesame amount as in 2016.

“This may be a temporary break in the trend,” said Ross Bremen,a partner and defined-contribution strategist at NEPC.Many employers are searching for new record-keepers thisyear, and that often means negotiating on costs, so “fees willlikely be lower again next year,” he said.

Just over a third of the 123 defined-contribution planssurveyed, which represent $138 billion in total assets,reported that they had been able to get a lower fee for at leastone of the investments offered in their 2016lineups.

Eleven percent of the plans added an index fund option lastyear.

There’s room for improvement in plan investmentoptions. About 18 percent of plans offered asingle passive investment, generally a low-cost investmentsthat track a broad index.

About a third of the 401(k) plans offered four passive investments.The median plan had three passive coreinvestment options; the most common asset classes coveredwere large-cap stock, international stock, andintermediate bond.

That weighted-average expense ratio of 0.41 percent meansmany investors are paying more than 0.41 percent, at a time whenmany index funds charge investors next to nothing. (Theaverage expense ratio is weighted by the asset size of funds sothat funds with few assets and high fees don’t skewthe ratios.)

For example, mom-and-pop investors without the negotiatingleverage of a company plan can pay 0.04 percent to invest$10,000 in the Vanguard Total Stock Market Index Fund. Over 30years, the difference between 0.04 percent and 0.41 percent isconsiderable.

While much of the investment world has gravitated towardlower-cost, passively managed index funds, a lot of the older moneyin 401(k) plans remains in actively managed funds.

“It takes a long time for trends to shift in thedefined-contribution world,” Bremen said. “Previously investedmonies don’t migrate quickly.”

A lot of the newer money is in target-date funds (TDFs),since these diversified funds, which adjust asset allocationaccording to an investor’s years to retirement, are thedefault investment option for most plans.

The survey found assets in target-date funds at an all-time highfor the 12 years it has been done, at 34 percent ofassets.Administrative fees also took a break from thesteady decline. In recent years, more 401(k) plans have movedto record-keeping contracts that charge by the participant, a moretransparent fee arrangement than many plans had earlier.

The survey found that the median per-head amount has risen to$59, from $57 last year. Until this year, the per-head amount haddropped every year since 2010, when it was $103.

As profit margins for record-keeping businesses shrink, otherfees tend to crop up in the mix.

“It’s a little like squeezing a balloon,” Bremen said. “Asrecord-keeping fees come down, you see managed-account fees, loanfees, brokerages fees go up. It’s a little bit of agame.”

Managed accounts, which offer a more personalized investmentstrategy than you see in, say, a target-date fund, for a higherfee, are offered by 28 percent of the plans surveyed, up from16 percent in 2013. But since the usual behavior by planparticipants is inertia, “so far they haven’t proved tobe a magic bullet,” Bremen said.

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