Quick Answer
Controlled group rules treat related companies (80%+ common ownership) as one employer for 401(k) purposes. This affects contribution limits, nondiscrimination testing, and eligibility. An employee working for two companies in a controlled group has combined compensation limits and cannot exceed $23,500 total deferrals across both plans.
Best Answer
Marcus Rivera, CFP
Executives and business owners who may be affected by controlled group aggregation
What are controlled group rules?
Controlled group rules require related companies to be treated as a single employer for retirement plan purposes. This happens when companies have at least 80% common ownership, either directly or indirectly.
Types of controlled groups:
How this affects your 401(k) contributions
When companies are in a controlled group, employees are subject to combined limits and testing:
Contribution limits are aggregated:
Real-world example: Brother-sister controlled group
Sarah owns 85% of both Tech Solutions LLC and Consulting Partners Inc. Her son Mark works as CFO of Tech Solutions ($180,000) and also consults part-time for Consulting Partners ($40,000).
Mark's situation:
Tech Solutions 401(k):
Consulting Partners 401(k):
Impact on nondiscrimination testing
Controlled groups must pass nondiscrimination tests as if they were one company:
Actual Deferral Percentage (ADP) test: Compares HCE vs. non-HCE deferral rates across all controlled group companies.
Example of failed testing:
If Tech Solutions has mostly high earners who defer 15% of pay, but Consulting Partners has lower-paid workers who defer only 3%, the combined ADP test might fail. This could force refunds of excess deferrals to highly compensated employees.
Key complications for business owners
Attribution rules: Ownership can be attributed through family members:
Example: If John owns 60% of Company A and his wife owns 25% of Company B, John is considered to own 85% of both companies (60% + 25% through attribution).
Strategic considerations
Plan design coordination: All controlled group plans should have compatible:
Contribution optimization: High earners should:
1. Maximize deferrals to the plan with better investment options
2. Ensure adequate lower-paid employee participation for testing
3. Consider safe harbor designs to avoid testing issues
What you should do
1. Determine if controlled group rules apply — work with a benefits attorney to analyze ownership structures
2. Coordinate contribution strategies across all related company plans
3. Monitor nondiscrimination testing — failed tests can force refunds and penalties
4. Consider plan design changes — safe harbor plans can eliminate most testing requirements
5. Calculate your total compensation impact using our paycheck calculator
[See how controlled group rules affect your paycheck →](paycheck-calculator)
Key takeaway: Controlled group rules can significantly limit 401(k) contributions and complicate plan administration for employees of related companies, requiring careful coordination of contribution strategies and plan design.
*Sources: [IRS Publication 560](https://www.irs.gov/pub/irs-pdf/p560.pdf), IRC Sections 414(b), 414(c), and 414(m)*
Key Takeaway: Controlled group rules can significantly limit 401(k) contributions and complicate plan administration for employees of related companies, requiring careful coordination of contribution strategies and plan design.
Controlled group impact on 401(k) limits
| Situation | Employee Deferral Limit | Annual Additions Limit | HCE Determination |
|---|---|---|---|
| Single employer | $23,500 | $70,000 per plan | Based on single employer pay |
| Multiple unrelated employers | $23,500 total | $70,000 per plan | Separate for each employer |
| Controlled group employers | $23,500 total | $70,000 per plan | Based on combined pay from all controlled group companies |
More Perspectives
Sarah Chen, CPA
Older workers who may have ownership interests or work for family businesses affected by controlled group rules
How controlled groups affect retirement catch-up strategies
For workers 50+ in controlled group situations, these rules can significantly impact your final years of retirement savings, especially if you're transitioning to part-time work or consulting arrangements.
Common scenario: Transitioning to consulting
Many pre-retirees move from full-time employment to consulting with their former employer or related companies. If there's common ownership, controlled group rules apply:
Example: At 62, you retire from ABC Corp but continue consulting through XYZ Consulting, which ABC's owner also controls (85% ownership).
Impact on catch-up contributions
Controlled group rules don't change catch-up limits, but they affect how you can use them:
Key planning considerations
Before accepting consulting arrangements with related companies:
1. Verify if controlled group rules apply
2. Understand how your HCE status might change
3. Plan deferral allocation between multiple plans
4. Consider timing of consulting income to optimize contributions
Key takeaway: Pre-retirees in controlled group situations must carefully coordinate catch-up contributions across related company plans to maximize retirement savings while avoiding compliance issues.
Key Takeaway: Pre-retirees in controlled group situations must carefully coordinate catch-up contributions across related company plans to maximize retirement savings while avoiding compliance issues.
Marcus Rivera, CFP
Employees working for multiple companies that may be related under controlled group rules
When multiple jobs become a controlled group issue
Many employees don't realize their seemingly separate jobs may be related under controlled group rules, creating unexpected limitations on their 401(k) contributions.
Common scenarios triggering controlled group rules
Family business connections: Working for your uncle's construction company while also employed at your cousin's related supply business (if same family members own 80%+ of both).
Corporate subsidiaries: Working part-time for ABC Marketing while your main job is at ABC Holdings — even if you didn't know they were related.
Private equity/venture capital: Multiple portfolio companies under the same investment fund may be treated as a controlled group.
How to identify if you're affected
Signs your multiple employers might be in a controlled group:
Practical impact on your contributions
If your multiple jobs are in a controlled group:
1. Combined deferral limit: $23,500 total, not per plan
2. HCE status: Based on combined compensation from all controlled group companies
3. Testing impact: Your contribution behavior affects nondiscrimination testing across all related companies
Action steps:
1. Ask HR at both companies if they're related entities
2. Monitor your total deferrals across both plans
3. Optimize employer matching by contributing enough to each plan for full matches
4. Be prepared for potential refunds if testing fails
Key takeaway: Employees with multiple jobs must verify whether their employers are related under controlled group rules, as this limits total 401(k) deferrals to $23,500 across all related company plans.
Key Takeaway: Employees with multiple jobs must verify whether their employers are related under controlled group rules, as this limits total 401(k) deferrals to $23,500 across all related company plans.
Sources
- IRS Publication 560 — Retirement Plans for Small Business
- IRC Section 414(b) — Controlled group definitions
- IRC Section 414(c) — Trades or businesses under common control
Reviewed by Marcus Rivera, CFP on February 28, 2026
This content is for educational purposes only and is not a substitute for professional tax advice. Consult a qualified tax professional for advice specific to your situation.