What drives the cost of setting up a 401(k)
There is no single price for starting a 401(k), because a plan is not one product. It is a set of jobs that someone has to do. What you pay depends on which of those jobs you buy separately, how much manual work your setup leaves behind, and which federal credits you qualify for.
A 401(k) has no single setup price. Cost tracks how many service roles you buy separately, whether payroll data reaches the plan by hand, whether the plan needs an annual audit, and which federal credits you qualify for.
Employers asking what a 401(k) costs usually get a number back with no explanation of what produced it. The number is less useful than the structure behind it, because the structure is what you can actually change. This page describes that structure. It does not quote prices — for what plans actually cost across the market, filed Form 5500 data is the honest source, and that analysis lives on thinknirvana.org.
The jobs a 401(k) requires
Every 401(k), from the smallest to the largest, needs the same set of jobs done. The IRS describes plan startup as four steps: adopt a written plan, arrange a trust for the plan's assets, develop a recordkeeping system, and provide plan information to eligible employees. Those four steps map onto a set of ongoing roles.
- Plan document — the written program that governs the plan. It must be a definite written program communicated to employees, and it has to be kept current as the law changes.
- Trustee and custodian — 401(k) plans are funded through a trust that holds and invests plan assets. The IRS notes the trustee may be the business owner, an employee, or a financial or trust institution.
- Recordkeeping — tracking each participant's contributions, earnings, elections and balances.
- Plan administration — eligibility tracking, required notices, compliance testing, and the annual return.
- Investment selection and monitoring — choosing the menu and reviewing it against a written policy.
- Independent audit — required for larger plans only, and the threshold is more forgiving than most employers expect. See below.
Naming these roles is not a criticism of anyone who fills them. They are structural facts about how retirement plans work, and understanding them is the difference between comparing quotes and comparing structures.
What actually moves the cost
| Driver | Why it moves cost | What reduces it |
|---|---|---|
| Number of separate providers | Each role bought separately carries its own contract, its own onboarding and its own hand-off. Hand-offs are where the manual work accumulates. | Roles held together under one arrangement, so the hand-offs disappear rather than being managed. |
| How payroll data reaches the plan | Every pay period, someone has to move eligibility, compensation and deferral data. Done by hand, that work recurs forever and is a common source of correction. | A direct payroll connection, so the same data moves without being retyped. |
| Plan design complexity | Custom eligibility, multiple entry dates, unusual match formulas and vesting schedules each add tracking that someone has to perform and verify. | A design that uses standard rules — for example a safe harbor design, which removes annual ADP and ACP testing entirely. |
| Annual independent audit | An audit is a separate professional engagement on top of everything else. | Staying under the participant threshold, which changed in your favour in 2023. See the next section. |
| Whether you are converting an existing plan | A conversion adds asset transfer, blackout notices, reconciliation of prior records, and diligence on the old plan's compliance history. | Nothing removes this work, but knowing it exists prevents a conversion quote being compared against a startup quote. |
| Federal startup credits | Credits do not lower the price. They offset it against tax, which is not the same thing and depends on your circumstances. | Checking eligibility properly before assuming an offset. Conversions and owner-only businesses often get nothing. |
This table describes what varies. It deliberately attaches no figures to any role — see the note on pricing below.
The audit threshold changed, and it favours small employers
Plans that cross a participant threshold must include an independent qualified public accountant's report with the annual Form 5500. That is a real professional engagement and a real cost, so where the threshold sits matters.
The counting method changed for 2023 plan years. A defined contribution plan's participant count for the 100-participant threshold is now based on the number of participants with an account balance at the beginning of the plan year. The previous method counted everyone eligible to participate, including employees who never enrolled and had no balance. The Department of Labor estimated that this change alone moved roughly 18,700 defined contribution plans into small-plan filing status, where the audit requirement can be waived.
For a small employer with modest take-up, that is often the difference between needing an audit and not. It is worth confirming which method your provider is applying, because a plan filing under the old method may be buying an audit it no longer needs.
The federal credits, and their conditions
Two federal credits can offset startup cost. Both have conditions that are easy to miss, and both reduce tax rather than reducing price.
The retirement plan startup costs credit under Internal Revenue Code §45E covers ordinary and necessary costs of establishing or administering a plan, for up to three years. It is worth up to $5,000 per year. For employers with 50 or fewer employees the credit is 100% of eligible startup costs; for those with 51 to 100 employees it is 50%. In either case it is capped at the greater of $500, or the lesser of ($250 × the number of eligible non-highly compensated employees) or $5,000.
Separately, a credit of $500 per year for a three-year period is available beginning with the first taxable year the employer includes an automatic enrollment feature.
Three conditions that disqualify more employers than expected. The startup credit requires at least one participant who is a non-highly compensated employee, so owner-only businesses do not qualify. It is not available if the employer maintained a qualified plan covering substantially the same employees in the three tax years before the first credit year, so most conversions get nothing. And it is limited by tax liability. Never treat the maximum as the expected amount — the eligible-NHCE cap is usually what determines the real figure. Confirm with a qualified tax advisor.
A note on what this page does not say
This page quotes no prices, no market averages and no percentages, and it names no provider. That is deliberate. A published average tells you what other businesses agreed to pay, not what your plan should cost, and a comparison built on one is usually shaped to flatter whoever published it. What is worth comparing is the structure: how many separate arrangements, how much recurring manual work, and who carries which duty.
A pooled employer plan changes that structure rather than the line items — participating employers join one plan with one provider holding the plan administrator role, instead of running a plan each. What that means in practice is covered in the guides linked below.
Common questions
How much does it cost to set up a 401(k) for a small business?
There is no single figure, because a 401(k) is a set of jobs rather than one product. Cost tracks how many of those jobs you buy separately, whether payroll data moves automatically or by hand, whether your plan needs an annual audit, and which federal credits you qualify for. Filed Form 5500 data is the honest source for what plans actually cost across the market.
Does the SECURE 2.0 startup credit make a 401(k) free?
No. The §45E credit reduces tax rather than price, is worth up to $5,000 per year for up to three years, and is capped at the greater of $500 or the lesser of $250 per eligible non-highly compensated employee or $5,000. It requires at least one non-highly compensated participant, is unavailable if you maintained a qualified plan covering substantially the same employees in the prior three tax years, and is limited by your tax liability. Consult a qualified tax advisor.
Does a small business 401(k) need an annual audit?
Only above the 100-participant threshold. For 2023 and later plan years, a defined contribution plan counts participants with an account balance at the beginning of the plan year, not everyone eligible to participate. The Department of Labor estimated the change moved roughly 18,700 plans into small-plan filing status, where the audit requirement can be waived.
Why is a plan conversion quoted differently from a new plan?
A conversion adds work a startup does not have: transferring assets, issuing blackout notices, reconciling the prior recordkeeper's data, and reviewing the old plan's compliance history. It also usually forfeits the §45E startup credit, because that credit is unavailable where a qualified plan covered substantially the same employees in the prior three tax years.
Sources
- Internal Revenue Service, 401(k) Resource Guide — Starting Up Your Plan — the written plan requirement, the trust and who may serve as trustee, and the plan information owed to participants
- Internal Revenue Service, Retirement Plans Startup Costs Tax Credit — the §45E credit amounts, the 50-or-fewer and 51-to-100 percentages, the cap formula and the eligibility conditions
- Internal Revenue Service, About Form 8881, Credit for Small Employer Pension Plan Startup Costs — how the startup and automatic enrollment credits are claimed
- U.S. Department of Labor, Changes for the 2023 Form 5500 and Form 5500-SF Annual Return/Reports — the participants-with-account-balances counting method for the 100-participant threshold, and the number of plans it moved into small-plan filing status
- Internal Revenue Service, 401(k) Plan Overview — annual ADP and ACP testing for traditional plans, and that safe harbor designs remove it
aipep401k.com is a pooled employer plan for small business 401(k) plans, operated by ThinkNirvana Foundation — plan administration handled by automation rather than assembled by hand.
Related: how long setting up a 401(k) actually takes, the steps to start a plan. To see what a plan design would look like for your own headcount, the plan design tool is free and needs no sign-up.