IRS Publication 4222 – 401(k) Plans for Small Businesses – Small business owners looking to attract top talent, reduce taxable income, and help employees build retirement security often turn to 401(k) plans. IRS Publication 4222, 401(k) Plans for Small Businesses, serves as the official, free joint resource from the IRS and U.S. Department of Labor (DOL) Employee Benefits Security Administration (EBSA).
This 19-page guide (Rev. November 2020, Catalog Number 37055P) remains the authoritative reference for traditional and safe harbor 401(k) plans. It walks employers through setup, operation, compliance, and responsibilities. While the core rules haven’t changed, contribution limits and cost-of-living adjustments update annually.
Download the full PDF here: IRS Publication 4222 (PDF).
Why Small Businesses Should Offer a 401(k) Plan?
A 401(k) plan delivers powerful advantages for both employers and employees:
- Tax benefits — Employee salary deferrals (pre-tax) lower current taxable income. Employers deduct contributions. Earnings grow tax-deferred (or tax-free for qualified Roth distributions).
- Talent attraction and retention — Competitive benefits help small businesses compete with larger employers.
- Flexibility — Employers choose contribution types (none, matching, nonelective, or both) and can change them yearly based on cash flow.
- Employee control — Participants direct investments and decide contribution amounts (within limits).
- Portability — Employees take their accounts when they leave, simplifying administration.
Publication 4222 emphasizes that 401(k) plans benefit rank-and-file employees and owners/managers alike, promoting proportional retirement savings.
Types of 401(k) Plans Covered in Publication 4222
The guide focuses on two main types suitable for businesses of any size:
- Traditional 401(k) Plan
Most flexible option. Employers may contribute (or not), match employee deferrals, or combine both. Subject to annual nondiscrimination testing (ADP/ACP tests) to ensure benefits favor non-highly compensated employees fairly. Employer contributions can vest over time. - Safe Harbor 401(k) Plan
Avoids annual testing by providing mandatory employer contributions (either matching or 3% nonelective to all eligible employees). These contributions vest immediately (100%). Ideal for businesses wanting simplicity and guaranteed compliance.
Note: The publication references automatic enrollment 401(k) plans (detailed in separate Publication 4674) and notes SIMPLE 401(k) plans for businesses with ≤100 employees (covered in Publication 560 and related guides).
How to Establish a 401(k) Plan: 4 Essential Steps (Per Publication 4222)?
Setting up a plan is straightforward, especially with pre-approved documents from financial institutions.
- Adopt a written plan document — The legal foundation. Use IRS-pre-approved prototypes or volume submitter plans to simplify compliance.
- Arrange a trust for plan assets — Assets must be held in trust (or insurance contracts) for exclusive benefit of participants and beneficiaries. Appoint a trustee.
- Develop a recordkeeping system — Track contributions, investments, earnings, distributions, and expenses. Most providers handle this.
- Provide information to eligible employees — Distribute the Summary Plan Description (SPD) and notify employees of rights and features.
You can handle setup yourself or work with a bank, mutual fund company, insurance firm, or third-party administrator (TPA).
Pro Tip: Use the IRS 401(k) Checklist (Publication 4531) alongside Publication 4222 for a quick compliance review.
2026 401(k) Contribution Limits (Updated Annually)
Publication 4222 lists older limits, but the IRS adjusts them yearly. Here are the official 2026 figures:
- Employee elective deferrals (pre-tax or Roth): $24,500
- Catch-up contributions (age 50+): $8,000 (ages 50–59 or 64+); $11,250 (ages 60–63 under SECURE 2.0)
- Total annual additions (employee + employer): $72,000 (or $80,000+ with catch-up for those 50+)
Limits apply per participant. Employer contributions (matching or nonelective) have no separate dollar cap beyond the overall annual additions limit. Always confirm the latest limits on IRS.gov, as they adjust for inflation.
Roth 401(k) contributions are also available and grow tax-free.
Operating Your 401(k) Plan: Key Rules and Responsibilities
Once established, ongoing duties include:
- Eligibility — Generally, employees age 21+ with 1 year of service. Plans may be more generous.
- Vesting — Employee deferrals and safe harbor contributions vest immediately (100%). Traditional employer contributions may vest gradually.
- Nondiscrimination Testing — Traditional plans require annual ADP/ACP tests. Safe harbor plans skip this.
- Depositing Contributions — As soon as reasonably segregable from general assets (generally within 7 business days for small plans).
- Investment Choices — Participants usually self-direct among a diversified menu. Employers must prudently select and monitor options.
Fiduciary Responsibilities (Critical Section in Publication 4222)
Fiduciaries (anyone with discretionary control over the plan or assets) must:
- Act solely in participants’ best interests.
- Follow plan terms and ERISA prudence standards.
- Diversify investments.
- Pay only reasonable expenses.
Hire service providers carefully, document decisions, and provide fee disclosures. Bonding is usually required. Publication 4222 stresses that fiduciary mistakes can lead to personal liability—consult professionals.
Reporting, Disclosure, Distributions, and Termination
- Annual Form 5500 (or 5500-SF/EZ) filing required for most plans.
- Participant disclosures — SPD, individual benefit statements, fee information, blackout notices.
- Distributions — Available at retirement, termination, or certain hardships. Rollover options preserve tax advantages.
- Plan termination — Possible if business needs change; requires full vesting and asset distribution.
Errors can often be corrected through IRS/DOL voluntary programs (see Publication 4224).
Additional Resources from IRS and DOL
Publication 4222 lists these helpful joint guides:
- Publication 3998: Choosing a Retirement Solution for Your Small Business
- Publication 4674: Automatic Enrollment 401(k) Plans for Small Businesses
- Publication 560: Retirement Plans for Small Business (SEP, SIMPLE, Qualified Plans)
- Publication 4531: 401(k) Plan Checklist
- Publication 4224: Retirement Plan Correction Programs
Visit IRS.gov/retirement-plans or DOL.gov/ebsa for the Small Business Retirement Savings Advisor tool.
Final Thoughts: Start Your 401(k) Plan Today
IRS Publication 4222 remains the go-to handbook for small businesses implementing or maintaining a 401(k) plan. Its clear, step-by-step guidance removes much of the complexity while emphasizing compliance and fiduciary duty.
Whether you choose a traditional or safe harbor design, a 401(k) plan is one of the most powerful tools for building employee loyalty and securing your own retirement. Download the PDF, review the 2026 limits, and consult a qualified retirement plan professional or financial advisor to tailor the plan to your business.
Ready to take the next step? Contact the DOL toll-free at 866-444-3272 or explore IRS resources today. Offering a 401(k) plan could be the smartest investment your small business makes in 2026 and beyond.
Sources: IRS Publication 4222 (Rev. 11-2020), IRS.gov retirement plan pages (reviewed/updated 2025–2026), Notice 2025-67 (2026 COLA adjustments), and related DOL publications. Always verify latest limits and rules on official IRS/DOL websites.