IRS Publication 6393 – IRS Forms, Instructions, Pubs 2026 – In the complex world of employee benefit plans, ensuring compliance with IRS regulations is crucial for employers and plan administrators. IRS Publication 6393, titled “Employee Benefit Plans: Explanation No. 5 Safe Harbor Nondiscrimination Requirements Defined Contribution Plans,” serves as a key resource for navigating these rules. This guide explains how defined contribution plans can meet nondiscrimination requirements through design-based safe harbors, helping plans avoid discriminatory allocations that favor highly compensated employees (HCEs). Released in its revised form in June 2021, it remains a foundational document for plan qualification under IRC Section 401(a)(4).
Whether you’re a business owner setting up a retirement plan or a benefits professional reviewing compliance, understanding these safe harbors can streamline plan design and reduce the need for annual testing. In this SEO-optimized article, we’ll break down the publication’s key elements, including requirements, examples, and practical implications, drawing from official IRS guidance and related resources.
What Are Safe Harbor Nondiscrimination Requirements?
Defined contribution plans, such as profit-sharing or money purchase pension plans, must ensure that contributions and benefits do not discriminate in favor of HCEs. Under Treasury Regulation Section 1.401(a)(4)-2(b), design-based safe harbors provide a straightforward way to satisfy the “nondiscrimination in amount” requirement without extensive data testing. These safe harbors focus on the plan’s structure, ensuring uniform allocations based on compensation or other nondiscriminatory formulas.
The publication is used alongside tools like Form 5627 (Worksheet 5) and Form 6045 (Deficiency Checksheet 5), which help evaluate compliance but are not submitted to the IRS. It’s particularly relevant for plans submitting applications under the 2020 Required Amendments List (RA List) per Notice 2020-83. Note that while these safe harbors address allocation nondiscrimination, they do not cover all aspects of IRC Section 401(a)(4), such as operational requirements or coverage testing under Section 410(b).
Key Design-Based Safe Harbors for Defined Contribution Plans
The core of Publication 6393 outlines two primary safe harbors: the uniform allocation formula and the target benefit plan safe harbor. Employers must select and adhere to one to qualify.
Uniform Allocation Formula (Non-Target Benefit Plans)
This safe harbor applies to most defined contribution plans, excluding target benefit plans. It requires that contributions and forfeitures be allocated uniformly as:
- The same percentage of compensation,
- The same dollar amount per participant, or
- The same dollar amount per unit of service (up to one week).
Elective deferrals under 401(k) and matching contributions under 401(m) are excluded from this formula.
Plans can still qualify even with certain variations, such as:
| Variation | Description |
|---|---|
| Section 415/409(n) Limits | Allocations limited by maximum contribution rules. |
| Uniform Caps | Dollar or percentage limits applied consistently, or only to HCEs. |
| Eligibility Conditions | Last-day or up to 1,000-hour requirements, with exceptions for retirement, disability, death, or military service. |
| Permitted Disparity | Integration with Social Security under Section 401(l). |
| Multiple Entry Dates | Allowed without impacting uniformity. |
| Lower HCE Allocations | HCEs may receive less than non-HCEs. |
| Combined Formulas | Allocations as the greater of or sum of multiple safe-harbor-compliant formulas, including top-heavy minimums. |
However, age- or service-weighted allocations disqualify the plan from this safe harbor. This structure is ideal for profit-sharing plans seeking simplicity.
Target Benefit Plan Safe Harbor
Reserved for pre-approved specimen plans (not individually designed), target benefit plans are money purchase pension plans where contributions aim to fund a “target” benefit, typically a straight life annuity at normal retirement age (NRA). Actual benefits depend on investment performance.
Key requirements include:
- Stated Benefit Formula: Must satisfy defined benefit safe harbors (e.g., fractional rule, unit credit, or flat benefit) as if it were a defined benefit plan. For flat benefits, pro-rata reductions apply for service less than 25 years.
- Service Crediting: No credit for years before participation or non-compliance periods, with grandfathering for pre-1991 plans.
- Funding Method: Contributions calculated using a regulatory formula, with forfeitures reducing future contributions.
- No Employee Contributions: For the stated benefit.
- Permitted Disparity: Must comply with defined benefit rules (refer to Worksheet 5B).
- Age-Based Rules: No reduction in accruals due to age under Section 411(b)(1)(H); uniform post-NRA benefits required.
Funding involves theoretical reserves starting at zero, with interest rates between 7.5% and 8.5%. Contributions amortize differences between reserves and present values using the UP-84 mortality table. Adjustments for Sections 415 and 416 limits are permitted.
Nondiscriminatory Compensation Definitions
A critical component for any safe-harbor-reliant plan is using a compensation definition that satisfies Section 1.414(s)-1. Automatic safe harbor definitions include:
- Section 415(c)(3) Compensation: Includes wages, salaries, elective deferrals (e.g., under 401(k), 125, 132(f), 457), and self-employed earned income.
- W-2 Wages Plus: Section 3401(a) wages plus reportable amounts under 6041, 6051, and 6052.
- Safe Harbor Alternative: Starts with one of the above, excluding fringes, reimbursements, deferred compensation, and welfare benefits; includes overtime, bonuses, and commissions.
- Employer Elections: Uniform inclusions or exclusions of certain items.
Alternative definitions must be reasonable and not favor HCEs, allowing for de minimis disparities or rate-based imputations. For self-employed individuals, compensation is adjusted earned income, prorated based on non-HCE percentages, ensuring equivalence to employee definitions.
This ensures fairness, as highlighted in IRS issue snapshots, where plans basing allocations on compensation must avoid discriminatory definitions without annual testing.
Practical Implications and Compliance Tips
Adopting these safe harbors simplifies IRS reviews for individually designed plans, focusing on design compliance rather than full nondiscrimination testing. However, plans must still address related rules, like minimum participation (Publication 6388) or vesting (Publication 6389).
For 401(k) plans, note that while Publication 6393 covers general defined contribution safe harbors, separate “safe harbor” provisions under Sections 401(k) and 401(m) address ADP/ACP testing through mandatory employer contributions (e.g., 3% nonelective or matching formulas). These can overlap, offering dual benefits like bypassing top-heavy tests.
Employers should consult IRS Notice 2016-16 for mid-year changes to safe harbor plans, ensuring notice and election conditions are met. As of 2026, with ongoing updates like those in SECURE 2.0 expanding eligibility for part-time workers, staying current is essential.
Conclusion: Why Safe Harbors Matter for Your Plan?
IRS Publication 6393 empowers plan sponsors to design compliant defined contribution plans efficiently, promoting equitable retirement savings. By leveraging uniform formulas or target benefits with nondiscriminatory compensation, businesses can minimize compliance risks and enhance employee benefits. For the latest guidance, visit IRS.gov or consult a tax professional to tailor these rules to your organization.