Controlled Groups: Rules and Recordkeepers That Support Them

Controlled group rules can be a “surprise” for growing companies—especially those with multiple entities, shared ownership, or recent acquisitions. The impact is real: it can change who must be counted as an employee for retirement plan purposes, how annual compliance testing works, and whether your plan tips into a large plan audit requirement.

Below is a practical guide to what a controlled group is, how to figure out if it applies to you, how plans are typically administered differently, and which common recordkeepers are often able to support controlled group plan administration.

What is a controlled group (in plain English)?

A controlled group is a set of two or more businesses that are treated as a single employer for certain retirement plan rules because of common ownership or control. This matters because retirement plan compliance often relies on employee counts, compensation, and participation—and controlled group rules can require you to combine those items across related companies.

Controlled group concepts show up in both IRS qualification rules and ERISA compliance. In practice, plan sponsors most often run into controlled group issues when:

• One owner (or a small group of owners) has significant ownership across multiple entities

• A parent company owns subsidiaries

• There are brother-sister companies with overlapping ownership

• A company buys or sells a business (M&A activity)

For regulatory background, the IRS provides an overview of retirement plan qualification requirements and related employer rules on its retirement plan resources page: IRS Retirement Plans. The U.S. Department of Labor also maintains guidance and resources for plan sponsors through EBSA: Employee Benefits Security Administration (EBSA).

How to know if you are in a controlled group

Start with the basics: map your ownership and management structure across all entities—LLCs, S-corps, C-corps, partnerships, and any commonly owned businesses (even if they operate in different industries). Controlled group determinations can be technical and fact-specific, so treat this as an initial screen, not a final legal conclusion.

Common indicators you may have a controlled group:

• The same person (or same small set of owners) owns significant portions of multiple companies

• One company owns a large stake in another company

• Entities share leadership, payroll, HR infrastructure, or centralized decision-making

• Acquisitions or new entities were added during the year

What to do next (recommended):

1. Collect documents: cap tables, operating agreements, shareholder agreements, and any purchase/sale documents.

2. Ask your TPA or advisor (if you have one) whether controlled group rules could apply and what data they need.

3. Confirm with an ERISA attorney: Controlled group status can affect plan qualification and fiduciary decisions. For help, you can find experienced counsel through our directory of ERISA attorneys.

If you’re also evaluating plan partners, our guide on how to hire a retirement plan advisor can help you ask the right questions about controlled group experience.

How plans often need to run differently for controlled groups

Once a controlled group exists, the biggest operational change is that certain plan rules must be applied as if all entities are one employer. That can affect day-to-day administration in several ways.

Common plan administration impacts include:

• Eligibility and entry dates: Employees of related entities may need to be included for eligibility tracking, depending on plan terms and rules.

• Coverage and participation: You may need to demonstrate that the plan benefits a broad enough group of employees across the controlled group (not just the owners’ entity).

• Compensation and hours: Data may need to be aggregated across entities for testing and allocations.

• Employer contributions: Matching or profit sharing can become more complex when different entities have different payroll systems or compensation structures.

• Plan document alignment: Some controlled groups use one plan that covers multiple entities; others use multiple plans that must still be tested together in certain ways.

These operational details are also why it matters whether your recordkeeper and TPA can support controlled group reporting and data aggregation.

What controlled group status means for employees

For employees, controlled group rules can be a good thing: they can prevent employers from excluding certain groups of workers by splitting operations into multiple companies. Practically, it can mean employees may become eligible sooner than expected or must be counted when determining whether the plan meets fairness requirements.

Employees may be impacted through:

• Eligibility: Service with a related company may need to be recognized (depending on plan terms and legal requirements).

• Access to benefits: A plan that historically covered only one entity may need to expand coverage or adjust contributions.

• Nondiscrimination protections: Controlled group testing is designed to ensure the plan doesn’t disproportionately favor owners and highly compensated employees.

From an HR perspective, communication is key—especially after acquisitions, reorganizations, or when onboarding a new entity into an existing plan.

How controlled groups impact annual compliance testing

Controlled group status commonly affects annual compliance testing because many tests look at who participates and who benefits—across the employer. When entities are treated as one employer, you may need to combine employee populations and data.

Testing areas that are often affected include:

• Coverage testing: Whether enough non-highly compensated employees benefit when considering the controlled group population.

• ADP/ACP testing (for 401(k) and match): Deferral and match rates may need to be evaluated with the combined group in mind.

• Top-heavy rules: Whether the plan is “top-heavy” can change when ownership and balances are analyzed across the controlled group.

• Contribution limits: Certain limits apply per person across plans within the controlled group, depending on circumstances.

When controlled group status is missed, the plan can drift into non-compliance—sometimes without obvious symptoms until testing fails or an auditor asks questions. If you’re concerned about downstream filing issues, it’s also helpful to understand what a Form 5500 is and the penalties for late or rejected Form 5500 audits.

How controlled groups can trigger (or change) large plan audit requirements

Many plan sponsors first learn about controlled group rules when they cross the threshold into a “large plan” audit. In general, large plan status is tied to participant counts reported on the Form 5500, and controlled group relationships can affect how you count employees/participants and how your plan is viewed for reporting and compliance purposes.

Even when a controlled group doesn’t automatically mean you need an audit, it can:

• Increase participant counts if additional entities’ employees are included in plan eligibility and participation

• Complicate audit scope because payroll, eligibility, and contributions may come from multiple entities and systems

• Increase documentation needs (ownership records, plan sponsor resolutions, adopting employer agreements, etc.)

• Increase costs: Costs of the EBP audit typically go up as many auditors charge per EIN and payroll provider.

If you’re unsure whether an audit is required, start with What Is a 401(k) Audit and When Do I Need One? and then review What Is Needed for a 401(k) Audit and Where Do I Find It?.

Which recordkeepers support controlled groups?

Many major recordkeepers can support controlled group plan administration, but “support” can mean different things in practice—such as handling multiple adopting employers under one plan, accepting aggregated payroll files from multiple FEINs, or coordinating controlled group testing with your TPA.

The following recordkeepers are commonly seen supporting controlled group structures (subject to plan design, service model, and specific implementation):

• Empower

• Fidelity Workplace Investing

• Transamerica

• Voya Financial

• Nationwide

Questions to ask any recordkeeper (and your TPA) before you commit:

• Can the platform support multiple adopting employers and multiple payroll sources?

• How do you handle eligibility tracking across entities (hours/service and rehires)?

• What is required for controlled group testing—and who performs it (recordkeeper vs. TPA)?

• Can you produce reports needed for Form 5500 and (if applicable) the annual audit?

• What is the process when we acquire or divest an entity mid-year?

Also consider whether you need additional specialists as complexity increases, such as 401(k) financial advisors to help govern the plan, or a review of bonding requirements via What Is An ERISA Bond And How To Buy One? and our directory of ERISA bond providers.

Conclusion: treat controlled group status as a growth milestone

If your business has multiple entities, shared ownership, or recent M&A activity, controlled group rules can materially affect plan eligibility, annual compliance testing, and audit readiness. The safest approach is to identify potential controlled group relationships early, confirm the determination with counsel, and make sure your recordkeeper/TPA can administer the plan correctly across all entities.

Need help validating your structure or preparing for testing and audit impacts? Start by consulting an ERISA attorney, and if you’re facing an audit requirement or want to be proactive, connect with experienced 401(k) auditors who regularly work with multi-entity employers.