Owner resources

Owner Retirement Plans: Solo 401(k) vs SEP vs Safe-Harbor 401(k)

The useful question is not which plan has the flashiest name. It is the retirement plan you can offer your team — and yourself — in a way that fits payroll, cash flow, and how your CPA already prepares the return.

Educational only. Not personalized investment, tax, or legal advice. Vital Investment Management, LLC is a fee-only fiduciary and SEC-registered RIA (CRD #300811). Led by Dillon Goodman, CPA, CFP®, for Northern Colorado business owners.

Start with who is on the payroll

Plan design begins with headcount and how you pay yourself. A solo owner with no common-law employees has a different menu than an owner with a W-2 team. Adding employees does not only change paperwork; it can change which plan type fits, how much the company must contribute for staff, and how your personal deferrals sit next to payroll taxes. Your CPA and plan administrator should see the same facts before anyone picks a product.

Solo 401(k)

A solo 401(k) (sometimes called an individual 401(k)) is generally for a business with no employees other than the owner and, in many cases, a spouse who works in the business. It can allow both employee deferrals and employer contributions under the plan’s rules. It often appeals to owners who want a single plan that can hold traditional and Roth deferrals when the document allows it. It is usually a poor fit once you hire common-law employees who must be covered. Limits change by year; confirm current figures with your CPA and the plan document — this page does not publish dollar limits that would date the article.

SEP IRA

A SEP IRA is an employer-funded arrangement with relatively simple administration. Contributions are employer-side only; employees generally do not make elective deferrals into a SEP the way they would into a 401(k). When you have staff, SEP contribution formulas typically apply across eligible employees under the plan’s terms, so “a large contribution for me” can mean a matching obligation for the team. Owners who like SEPs often value simplicity. Owners who want employee deferrals and a different cost structure often look at a 401(k) instead.

Safe-harbor 401(k) when you have employees

A 401(k) with a safe-harbor design is a common path once you have a team and still want meaningful owner deferrals. Safe-harbor contributions (match or nonelective, as the plan document provides) are one way plans satisfy certain nondiscrimination tests so highly compensated owners are less likely to have deferrals limited by testing. That does not mean “free money” or a tax outcome. It means the company commits to a defined contribution pattern for eligible employees in exchange for a more predictable testing result. Setup, notices, payroll integration, and Form 5500 obligations are real work — coordinate with a recordkeeper and your CPA.

CPA angle: plan design next to the tax return

Dillon Goodman is a CPA and CFP®. On owner plans, the fee-only advisory conversation sits next to — not instead of — the tax preparer’s work. Entity type, owner compensation, estimated taxes, and timing of employer contributions all change what “maxing the plan” means in a given year. Vital coordinates with the owner’s tax preparer and does not prepare returns or act as plan counsel. Plan documents, discrimination testing, and fiduciary plan roles belong with qualified plan professionals.

How to choose without chasing a slogan

• Count employees who must be covered, including part-time rules under the plan you are considering.
• Write how much cash the company can commit every year for staff contributions — not only for the owner.
• Ask whether you need employee deferrals, Roth features, loans, or a solo structure that ends when you hire.
• Put your CPA, payroll provider, and plan administrator on the same fact sheet before you sign a document.

Related reading

• Financial planning for owners
• Wealth outside the company
• Tax-efficient investing for Colorado owners
• Cash management for business owners

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