Guide

How A Section 125 Plan Cuts An Employer's Payroll Tax Bill

Published 2026-09-12

A translucent glass funnel with golden coins pouring in and a thinner stream emerging below, a ribbon of cyan light carrying the difference away, pre-tax premiums reducing employer payroll tax — The same premium dollar, doing two jobs instead of one.

A Section 125 plan, often called a premium only plan when health premiums are the only benefit offered, lets employees pay their share of insurance premiums before tax is calculated. What most owners never hear is that the employer benefits automatically from the same mechanism. Salary reduction amounts are excluded from the statutory definition of wages for both Social Security and Medicare tax and for federal unemployment tax, and because the employer computes its own liability on that identical wage base, employer payroll tax falls in lockstep with the employee's. The saving is roughly seven and a half percent of every premium dollar routed through the plan, and it requires no election and no application. The single point of failure is the written plan document, which must exist and be effective before the plan year begins.

Quick Answer

Salary reduction contributions under a valid Section 125 plan are excluded from the definition of wages for FICA under IRC section 3121(a)(5)(G) and for FUTA under IRC section 3306(b)(5)(G).
Because employer payroll tax is computed on the same wage base, the employer saves roughly 7.65 percent of every pre-tax premium dollar, being 6.2 percent Social Security up to the 2026 wage base of $184,500 plus 1.45 percent Medicare with no limit.
A Section 125 plan must be a separate written plan adopted and effective on or before the first day of the plan year, and retroactive adoption is not permitted.
Without a valid written plan the arrangement is not a cafeteria plan at all, and every participating employee's election produces gross income, which removes the employer's exclusion as well.
Sole proprietors, partners in a partnership, more-than-2-percent S corporation shareholders and corporate directors may not participate in a cafeteria plan.

Ask a small employer what health insurance costs the business and the answer is a premium number. Ask what it saves the business and the room usually goes quiet.

That gap is where this sits. There is a structure that turns part of an insurance expense into a reduction of the employer’s own payroll tax, it requires no application to anyone, and a surprising number of Las Vegas businesses are running premium deductions through payroll without it.

How does a Section 125 plan reduce an employer’s payroll taxes?

A Section 125 plan changes what counts as wages, and payroll tax is calculated on wages. That single move is the whole mechanism.

When an employee elects to pay their share of health premiums through a Section 125 plan, the salary reduction amount is never actually or constructively received by the employee. Federal law therefore excludes it from the statutory definition of wages for Social Security and Medicare tax under IRC section 3121(a)(5)(G), and from wages for federal unemployment tax under IRC section 3306(b)(5)(G). The Instructions for Form 940^[1] list payments for benefits excluded under section 125 cafeteria plans among payments exempt from FUTA tax.

The employer computes its own liability on that same reduced wage base. No separate election, no filing, no approval. This is the rare provision where the employer saving is automatic and simultaneous with the employee’s.

The rates the reduction applies against

Three taxes move, at different rates and with different ceilings.

Employer tax	Rate	2026 base
Social Security	6.2%	wages up to $184,500
Medicare	1.45%	no limit
Combined employer FICA	7.65%
FUTA, net of full state credit	0.6%	first $7,000 per employee

Two details keep the estimate honest. There is no employer share of the 0.9 percent Additional Medicare Tax, which is employee-only, so it never appears in an employer saving. And state unemployment tax treatment is separate and state-specific, so it should not be folded into a federal number. Current rates and the wage base are published annually in IRS Publication 15^[2].

What does that actually save a Las Vegas employer?

Roughly seven and a half cents on every premium dollar the employees pay, which compounds quietly across a payroll. The figure sounds small until it is multiplied by a real headcount for a real year.

Consider a Spring Valley business with 18 employees, using entirely illustrative figures. Suppose 14 of them enroll in coverage and the employee share averages $210 a month. That is $2,940 a month routed through the plan, or $35,280 a year. At the combined 7.65 percent employer FICA rate, with every affected employee below the Social Security wage base, the employer’s payroll tax falls by about $2,699 for the year. FUTA adds a small further reduction on wages below the $7,000 per-employee base.

Those figures are invented to show the shape of the calculation. They are not a quote, not a projection, and not a substitute for a real payroll analysis. The saving moves with enrollment, with the employee contribution split, and with how many employees sit above the Social Security wage base.

The number is not life-changing on its own. What makes it interesting is that it is money the business is currently not capturing while already paying the premium, and it sits alongside the deduction the business already takes on its own share. Owners hearing both facts in the same sentence for the first time is a common moment in a benefits conversation, and it is the reason the honest framing of insurance is a structure rather than a line item, which is also the argument in the small business health insurance guide.

Why does the written plan document matter more than anything else?

Because without it there is no plan, and the failure is retroactive and total. A cafeteria plan must be a separate written plan, adopted and effective on or before the first day of the plan year. Retroactive adoption is not permitted.

The document has to specify each benefit offered, the eligibility rules, the election procedures including when elections become irrevocable, how employer contributions are made, the maximum contribution amount or the method of determining it, and the plan year.

If that document does not exist or fails the requirements, the arrangement is not a cafeteria plan and each employee’s election between taxable and nontaxable benefits produces gross income. Read that consequence carefully, because it runs in both directions. Every dollar deducted becomes taxable wages for every participant, the employer loses the FICA and FUTA exclusion it has been taking, and the exposure includes payroll tax, corrected W-2s, penalties and interest.

This is the single most common defect in small employer setups. A business starts deducting premiums pre-tax because the payroll software offers the option, nobody ever adopts a plan document, and the arrangement runs for years looking perfectly normal on every paystub. The paperwork is not paperwork. It is the only thing standing between the arrangement and full retroactive taxability.

One caveat on the authority. The detailed cafeteria plan regulations issued in 2007 remain proposed rather than final, and taxpayers generally rely on them. That is a reason to have a professional draft the document rather than to treat the requirement as soft.

Why elections lock for the year

Irrevocability is the trade for the tax treatment, and it surprises employees every January. An election made under a Section 125 plan is generally locked for the plan year, and the written document has to spell out the irrevocability rules and the periods during which elections are effective.

The logic is straightforward once stated. The exclusion depends on the employee never having actual or constructive receipt of the money, and an election an employee could reverse at will starts to look like access to cash. So the plan year is the unit, and mid-year changes are permitted only in defined circumstances tied to a change in status, with the plan document governing which ones that specific plan recognizes.

Practically, this is a communication problem more than a compliance one. An employee who picks a plan in November and has a baby in March needs to know a change is available and needs to know there is a window on it. An employee who simply changes their mind in February does not get to. The qualifying event mechanics that drive both mid-year benefit changes and coverage changes generally are covered in what is a qualifying life event and how long do you have after a qualifying life event.

Which events a given plan recognizes, and what documentation it requires, is a plan document question rather than a general rule, and getting it wrong on either side creates a correction nobody enjoys.

Who is not allowed to participate?

Owners, in most structures, and this is where the sales pitch usually falls apart if nobody says it out loud. Only employees may participate in a cafeteria plan.

Excluded from participating: sole proprietors, partners in a partnership, more-than-2-percent S corporation shareholders, and corporate directors acting solely as directors. IRS Publication 15-B^[3] states the S corporation rule directly, instructing employers not to treat a 2 percent shareholder as an employee for this purpose but as a partner in a partnership. Family attribution applies, so a spouse, child, parent or grandparent of a more-than-2-percent shareholder is treated as one too.

That has a blunt consequence for a very common Nevada business shape. A single-owner S corporation with no non-owner W-2 employees has effectively no employer payroll tax to save through a premium only plan, because the only person on payroll cannot participate. Anyone selling a POP into that situation is selling nothing.

What owners get instead

A different provision, with a different benefit. An owner excluded from the cafeteria plan generally takes the self-employed health insurance deduction under IRC section 162(l).

The distinction is worth being precise about, because it is the whole reason the two audiences need different advice. Section 162(l) is an above-the-line income tax deduction. It produces no FICA, SECA or FUTA saving whatsoever. A Section 125 plan produces payroll tax savings but only for W-2 employees who are not excluded owners. Same household, same premium, entirely different tax mechanics.

Realtors, 1099 contractors and other self-employed Nevadans working through what applies to them will find it in are health premiums deductible for 1099 contractors and in can self-employed Nevadans deduct health insurance premiums.

What does a Section 125 plan have to pass to stay compliant?

Three nondiscrimination tests, and a simpler path for plans that only handle premiums. A cafeteria plan must not discriminate in favor of highly compensated individuals or key employees.

The three are an eligibility test under section 125(b)(1)(A), a contributions and benefits test under section 125(b)(1)(B) requiring that similarly situated participants get a uniform opportunity to elect qualified benefits and that highly compensated participants not disproportionately elect them, and a key employee concentration test under section 125(b)(2).

Failing discrimination testing is unpleasant but contained. Publication 15-B is explicit that where a plan favors highly compensated employees, the value of the taxable benefits they could have selected goes into their wages. Note the asymmetry against the document failure above: a discrimination failure taxes the highly compensated only, while a written plan failure taxes everyone.

A premium only plan gets meaningful relief here. The proposed regulations create a safe harbor for premium only plans that meet certain requirements, implementing the safe harbor in section 125(g)(2), which substantially reduces the annual testing burden compared with a full flexible benefit plan. Separately, an eligible small employer with generally no more than 100 employees can use a simple cafeteria plan and obtain a safe harbor from the nondiscrimination testing by making employer contributions of either a uniform percentage of at least 2 percent of compensation, or the lesser of 6 percent of compensation or twice each qualified employee’s salary reduction contribution.

Go Deeper

ProtectHealth is an official Paychex partner. The plan document, the payroll configuration that makes it real, and the benefits strategy sitting on top all get handled in one conversation instead of three.

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What should an employer check before the next plan year?

Four checks, and the first one answers whether the rest matter.

Confirm a written plan document exists, and find out when it was adopted. Payroll software offering a pre-tax deduction checkbox is not a plan document. If nobody can produce one, the pre-tax treatment being applied right now has nothing holding it up.

Confirm the plan year on the document matches the plan year being run. A document adopted for a plan year that has since rolled over needs attention before the new year starts, not after.

Check who is coded as participating. A more-than-2-percent S corporation shareholder, a partner, or an owner’s spouse sitting in the participant list is a defect regardless of how long it has been there.

Run the actual numbers on current enrollment. The saving is a function of how many employees participate and what they contribute, so a plan with low enrollment is worth less than the same plan with good enrollment, which makes the benefits communication part of the tax outcome.

We are insurance nerds, not tax professionals. Whether a specific business has a valid plan, whether a particular owner is excluded, and how any of this lands on a specific return are questions for a licensed tax professional. What belongs here is making sure an employer knows the mechanism exists and knows which single document the whole thing depends on.

Employers working through the rest of the employer picture will find the state mandate in Nevada’s retirement plan mandate, the federal credits in the retirement plan tax credits guide, the administration question in PEO versus payroll service versus DIY, and the full framework in the ProtectHealth buyer’s guide.

The product should serve the strategy, not become the strategy. A premium only plan is a document. What it is actually for is making the same insurance spend do two jobs instead of one.

Sources

Internal Revenue Service — Instructions for Form 940
Internal Revenue Service — IRS Publication 15
Internal Revenue Service — Publication 15-B

Frequently Asked Questions

Do pre-tax premiums lower an employer's payroll taxes?

Yes. Salary reduction contributions under a valid Section 125 plan are excluded from wages for FICA under IRC section 3121(a)(5)(G) and for FUTA under IRC section 3306(b)(5)(G). Because the employer share is computed on that same wage base, employer Social Security, Medicare and federal unemployment tax all fall as employee pre-tax premium contributions rise.

What is a Section 125 premium only plan?

A premium only plan, or POP, is the simplest form of Section 125 cafeteria plan. It offers a single choice between taxable cash wages and paying the employee share of health premiums on a pre-tax basis, with no flexible spending account or other qualified benefits attached.

Can an S corporation owner participate in a Section 125 plan?

No. A more-than-2-percent S corporation shareholder is not treated as an employee for Section 125 purposes and may not participate. Sole proprietors, partners in a partnership and corporate directors acting solely as directors are excluded on the same basis, and family attribution rules apply to the 2 percent shareholder test.

Does a Section 125 plan need a written document?

Yes, and it is not a formality. A cafeteria plan must be a separate written plan adopted and effective on or before the first day of the plan year. Without a valid written plan the arrangement is not a cafeteria plan, and each participating employee's election between taxable and nontaxable benefits produces gross income.

How much does a Section 125 plan save an employer?

The employer saves its share of FICA on every dollar routed through the plan, which is 7.65 percent for employees below the Social Security wage base of $184,500 in 2026 and 1.45 percent above it, plus up to 0.6 percent net FUTA on wages below $7,000 per employee. There is no employer share of the Additional Medicare Tax.

What's the next step?

Nevada mandates retirement access, the federal credits that offset a real plan are generous, and pre-tax premiums cut employer payroll tax. ProtectHealth is an official Paychex partner, so the whole employer picture gets mapped in one conversation.