A defined contribution investment only (DCIO) arrangement is a distribution model in which an investment manager sells funds to a retirement plan and does nothing else. No recordkeeping, no participant website, no compliance filings. The plan sponsor hires separate specialists for those jobs. That separation lets sponsors build a fund lineup from multiple asset managers instead of accepting one company’s proprietary menu, and it makes the price of each service visible on its own line.
How the Unbundled Model Works
In a traditional bundled 401(k), one company handles investments, recordkeeping, compliance testing, and participant communications as a package. DCIO breaks that package apart. The investment manager runs the funds. A recordkeeper tracks balances and processes transactions. A third-party administrator handles compliance paperwork. Each provider is accountable for its own piece and charges its own fee.
ERISA requires plan fiduciaries to act “with the care, skill, prudence, and diligence” that a knowledgeable person would use when managing a similar plan.1Office of the Law Revision Counsel. 29 U.S. Code 1104 – Fiduciary Duties Unbundling supports that duty in two practical ways. When each service has its own contract, a fiduciary can replace an underperforming fund without disturbing the recordkeeping platform. And because each provider’s fee is stated separately, the sponsor can evaluate whether any single component is priced competitively. In a bundled arrangement, investment costs and administrative costs often blend together, which makes reasonableness harder to prove.
DCIO has caught on mainly among mid-size and large employers that want granular control over investment quality and fees. Smaller plans sometimes still find bundled service more practical, since running three vendor relationships takes more attention than running one.
Who Does What in a DCIO Plan
Three core providers make the structure work.
- The investment manager is typically a mutual fund company or asset manager that supplies the funds on the participant menu. Their job is portfolio construction and performance. They don’t talk to participants or maintain any technology. A single DCIO plan might use target-date funds from one firm, an index fund from another, and a stable value fund from a third.
- The recordkeeper is the plan’s technology backbone. It processes contributions, tracks individual balances, hosts the participant website, and executes trades when employees change investments. Industry surveys typically place average recordkeeping costs in the range of $45 to $80 per participant per year for mid-size plans, with smaller plans paying more and larger plans negotiating lower rates.
- The third-party administrator handles the compliance work the recordkeeper does not: nondiscrimination testing, the annual Form 5500 filing, and keeping the plan document current with tax law changes. Some recordkeepers include basic TPA services, but in a fully unbundled plan these functions sit with a separate firm.2Internal Revenue Service. Form 5500 Corner
Where the Financial Advisor Fits
Most DCIO plans also engage a financial advisor, and the type of engagement determines who carries investment liability. An advisor operating in a 3(21) capacity recommends funds but leaves the final decision to the plan sponsor. The sponsor accepts or rejects the recommendation and bears responsibility for the outcome. The 3(21) advisor shares fiduciary status but does not make binding choices for the plan.3eCFR. 29 CFR 2510.3-21 – Definition of Fiduciary
A 3(38) investment manager takes discretionary control of the fund lineup. They select, monitor, and replace investments without needing sponsor approval for each change. When a plan appoints a 3(38) manager, the plan’s trustees are generally not liable for that manager’s investment decisions.4Office of the Law Revision Counsel. 29 U.S. Code 1105 – Liability for Breach of Co-Fiduciary That liability shift is the main reason sponsors hire 3(38) managers in a DCIO structure. The sponsor still has to monitor how the manager is performing, at least annually. Delegation is not abdication, and hiring a 3(38) manager and then ignoring their work is itself a fiduciary failure.
Fees, Revenue Sharing, and Share Classes
Fee transparency is the strongest practical argument for DCIO, and ERISA’s service-provider disclosure rules are what make transparency enforceable. Under Section 408(b)(2), every covered service provider must give the plan fiduciary a written breakdown of services, whether the provider will act as a fiduciary, and all compensation the provider expects to receive, including indirect compensation like revenue sharing, 12b-1 fees, and sub-transfer-agent payments.5eCFR. 29 CFR 2550.408b-2 – General Statutory Exemption for Services or Office Space Without those disclosures, the service arrangement is not considered reasonable, and the fee itself becomes a prohibited transaction.6U.S. Department of Labor. Final Regulation: Service Provider Disclosures Under 408(b)(2)
Revenue Sharing
Many mutual fund share classes build in payments that flow from the fund company to the recordkeeper, effectively subsidizing recordkeeping through the fund’s expense ratio. In a bundled plan, participants often don’t realize they’re paying for recordkeeping through inflated investment fees. A DCIO plan using zero-revenue-share classes (like R6 or institutional shares) removes those hidden payments, and the recordkeeper charges a straightforward per-participant or asset-based fee instead.
Where a plan does use share classes that generate revenue sharing, the Department of Labor has taken the position that the plan’s contractual right to those payments is a plan asset.7U.S. Department of Labor. Advisory Opinion 2013-03A Fiduciaries have to track where the money goes. If revenue sharing exceeds what the recordkeeper is owed, the excess should be credited back to participant accounts or used to pay other legitimate plan expenses. Letting a service provider keep overpayments is the kind of thing that produces lawsuits.
Picking the Right Share Class
Choosing the right share class for each fund is one of the most consequential decisions in a DCIO implementation, and it’s where the model delivers the clearest cost savings. Institutional share classes (often labeled “I” shares) and retirement-plan-specific classes like R6 carry no 12b-1 marketing fees and no revenue-sharing payments. Institutional shares are typically designed for investors putting in $1 million or more, but DCIO platforms and retirement plans routinely qualify regardless of individual account balances. The cost difference between share classes of the same fund can run 30 to 50 basis points a year or more, which compounds into a meaningful drag on participant balances over a career.
Building the Investment Menu
The investment lineup is the whole point of going DCIO. Selection needs to be documented well enough that a regulator reviewing it years later can reconstruct the reasoning.
Investment Policy Statement
A well-run plan starts with an investment policy statement that lays out criteria for adding, monitoring, and removing funds. ERISA does not strictly require an IPS, but having one and following it is the most reliable way to demonstrate a prudent process if the plan is ever scrutinized.8eCFR. 29 CFR 2550.404a-1 – Investment Duties A useful IPS covers acceptable asset classes, benchmarks, expense ratio thresholds, and review frequency. It should be specific enough to constrain decisions but not so rigid that the committee cannot exercise judgment.
Target-Date Funds
Target-date funds are the default investment in most 401(k) plans, so choosing the right series matters. The DOL has published guidance on what fiduciaries should evaluate: how well the glide path (the shift from stocks to bonds over time) matches participant demographics, whether the fund reaches its most conservative allocation at the target date or continues adjusting afterward, and the total cost including both the target-date fund’s own fees and those of its underlying components.9U.S. Department of Labor. Target Date Retirement Funds – Tips for ERISA Plan Fiduciaries If the expense ratios of the component funds are substantially lower than the wrapper’s expense ratio, that gap needs an explanation. The DOL also suggests asking whether a custom target-date fund built from non-proprietary components would fit better. On a DCIO platform, that is actually feasible, because the platform already supports funds from multiple providers.
Collective Investment Trusts
Collective investment trusts (CITs) show up more and more on DCIO menus. CITs are pooled investment vehicles managed by banks or trust companies rather than registered investment companies. Because they are exempt from SEC registration, they carry lower regulatory overhead. Industry data shows CIT fees tend to run 10 to 30 basis points below comparable mutual funds, and for actively managed strategies the gap can be wider.
One boundary to know: CITs are only available to qualified retirement plans, primarily ERISA-governed 401(k) and pension plans. As of early 2026, 403(b) plans still cannot use CITs, because the securities law barrier was never resolved even though SECURE 2.0 addressed the tax treatment side. The INVEST Act passed the House in December 2025 and would fully authorize CITs for 403(b) plans, but it still requires Senate approval.
Keeping It Compliant
Setting up a DCIO arrangement is the straightforward part. Keeping it compliant over time is where most fiduciary failures happen, usually from inattention rather than bad intent.
The duty to monitor plan investments does not end when funds are selected. At least annually, the plan committee should review each fund’s performance against its benchmark, compare expense ratios to peer funds, and evaluate whether the original rationale for including the fund still applies.8eCFR. 29 CFR 2550.404a-1 – Investment Duties If a fund’s management team has turned over, its strategy has drifted, or its costs have crept up compared with alternatives, the committee has to document whether keeping it is still prudent. The IPS should specify the criteria and the timetable. Plans that use a 3(38) manager shift day-to-day monitoring to that manager, but the sponsor still has to evaluate whether the manager is doing the job competently.
Cybersecurity gets folded into that duty too. The DOL treats service-provider cybersecurity as a fiduciary matter, not just an IT concern, and expects fiduciaries to review each provider’s security program, audit results, incident history, and insurance coverage.10U.S. Department of Labor. Tips for Hiring a Service Provider With Strong Cybersecurity Practices With three or more providers in the picture, each one is an independent attack surface, and the review load scales accordingly.