Is the portion of a Utah employee's gross wages that the employee contributes to an employer's 401(k) plan subject to Utah income tax at the time of contribution, or is it deferred like it is for federal income tax purposes?

Plain-English summary

An accounting firm representing a Houston-based company with Utah employees asked the Utah State Tax Commission a straightforward withholding-tax question: when an employee elects to contribute part of their paycheck to a new 401(k) plan, is that contributed amount subject to Utah income tax right away, or is it deferred the same way it's deferred for federal income tax?

The Commission's answer was equally short: because 401(k) employee contributions are already tax-deferred at the federal level, those same contributions are also deferred for Utah income tax purposes. In other words, Utah simply follows the federal deferral treatment — the contributed wages aren't included in the employee's Utah taxable income (or subject to Utah withholding) at the time they're contributed to the plan.

What this means for you

Employers setting up or administering a 401(k) plan for Utah employees

You don't need a separate Utah-specific withholding calculation for the portion of wages employees elect to contribute to their 401(k) — per this ruling, Utah simply mirrors the federal tax-deferred treatment, so those contributed amounts are excluded from Utah wages subject to withholding at the time of contribution.

Employees contributing to a 401(k) while working in Utah

Your paycheck's 401(k) contribution reduces your Utah taxable wages the same way it reduces your federal taxable wages — you won't pay Utah income tax on that money until you eventually withdraw it (subject to whatever rules apply at that later point).

Payroll administrators/accountants handling multi-state 401(k) withholding questions

This ruling is a simple, useful confirmation that Utah's income tax treatment of 401(k) contributions tracks federal treatment rather than diverging from it — helpful when a client asks whether Utah requires any special adjustment beyond the federal deferral.

Common questions

Q: Do we need to withhold Utah income tax on the part of an employee's paycheck that goes into their 401(k)?
A: No, per this ruling — 401(k) contributions are deferred from Utah income tax the same way they're deferred federally, so they're excluded from Utah taxable wages at the time of contribution.

Q: Does this ruling address what happens when the employee eventually withdraws 401(k) funds?
A: No — this ruling addresses only the contribution-time question. It doesn't discuss the Utah tax treatment of later distributions or withdrawals.

Citations and references

No specific Utah Code or Administrative Rule sections were cited in this ruling's text; the Commission's answer rested on Utah's general practice of following federal tax-deferred treatment for 401(k) contributions.

Source

• Landing page: https://tax.utah.gov/commission/rulings/
• Original PDF: https://files.tax.utah.gov/tax/commission/ruling/95-066.htm

Original ruling text

95-066

Response
October 3, 1995

Request

XXXXX

UTAH STATE TAX COMMISSION

210 North 1950 West

Salt Lake City, Utah 84134-0180

Dear XXXXX:

Could you please provide written assistance with the following question regarding Utah withholding tax regulations. One of our clients, located here in Houston, has several employees in Utah. The client has recently decided to start a 401K Plan for it's employees and has the following question. Is the part of gross wages that is contributed to the 401K Plan by the employee subject to Utah State Income Tax at the time of the contribution or is it deferred?

Please send your response to the address listed below. Thank you in advance for your help.

Sincerely,

XXXXX

XXXXX

RE: Advisory Opinion - Employee contributions to a 401K Plan.

Dear XXXXX,

In response to your inquiry regarding application of Utah income tax laws to your client's 401K Plan, we offer the following information:

Since employee contributions made to a 401K Plan are tax deferred for federal income tax purposes, those contributions are also deferred for Utah income tax purposes.

If you have further questions, please write to this office again or call our Technical Research Section at XXXXX.

For the Commission,

Alice Shearer

Commissioner