SIMPLE IRA vs 401(k) Still Forces a Later Switch

For 2026, the IRS set the standard SIMPLE IRA deferral at $17,000 and the 401(k) deferral at $24,500, a $7,500 gap before any employer money. That is the comparison most small firms start with.

The bill that arrives later is the conversion. A SIMPLE IRA still demands a yearly employer check, generally bars a second plan, and drops you once headcount clears 100 people who earned $5,000.

What Are the 2026 SIMPLE IRA and 401(k) Limits?

The Internal Revenue Service posted the 2026 figures on November 13, 2025, in IR-2025-111 and Notice 2025-67. Employee elective deferrals to a 401(k), 403(b), governmental 457 plan, or the Thrift Savings Plan rise to the 401(k) deferral limit of $24,500 for 2026, up from $23,500. The standard SIMPLE cap moves to $17,000, up from $16,500.

SECURE 2.0 carved out a higher SIMPLE deferral for certain small shops. For 2026 that figure is $18,100, up from $17,600. Providers apply it to employers with 25 or fewer people who earned at least $5,000, and let firms with 26 to 100 people elect it if they raise the match to 4% or the nonelective contribution to 3%.

THE 2026 EMPLOYEE DEFERRAL CAPS

Catch-up money is where the plans drift further apart. A 401(k) participant who is 50 or older can add $8,000. A SIMPLE participant in the same age band can add $4,000, or $3,850 in the enhanced small-employer design. Ages 60 through 63 get a higher catch-up that stays $11,250 in a 401(k) and $5,250 in a SIMPLE plan.

Vendors now sell the SIMPLE IRA as a 401(k) lookalike after SECURE 2.0, minus the compliance file. The 2026 caps still leave a high earner tens of thousands short of the $72,000 defined contribution ceiling that a 401(k) can reach with employer money.

You Cannot Skip the Employer Check

A SIMPLE IRA is cheap to open because the employer has to fund it every year. The IRS makes you pick one of two formulas and stick with the notice you gave staff before the 60-day election window. You cannot turn the contribution off in a thin year.

HOW THE EMPLOYER CHECK WORKS

• The 3% match: You match each deferring employee dollar for dollar, up to 3% of that person’s pay, and the IRS does not apply the $360,000 compensation cap to this match.
• The 2% nonelective: You put 2% of pay into every eligible employee’s SIMPLE IRA, even if that person defers nothing, using pay up to $360,000 for 2026, which tops the credit at $7,200 per person.
• The 1% escape hatch: You may cut the match to as low as 1%, but only in 2 years out of the 5-year stretch that ends with the year you cut it, and only with advance notice.
• The extra nonelective: SECURE 2.0 lets you add a uniform extra nonelective contribution up to the lesser of 10% of pay or $5,000, on top of the required formula.

A 401(k) can match a lot, match a little, or skip the match. Safe harbor designs trade a set contribution for relief from nondiscrimination testing, but that is still a choice. The SIMPLE IRA’s required check is a condition of having the plan.

Cash flow is the part owners underestimate. If three staff defer and you also defer, a 3% match is a payroll cost you owe even if revenue dips. The 2% nonelective can cost more when many eligible people save nothing, because you fund all of them.

Paperwork Is Where SIMPLE Still Wins

A SIMPLE IRA is an IRA at a bank, insurer, or other custodian, opened with IRS Form 5304-SIMPLE or Form 5305-SIMPLE, or with a prototype document. The employee owns the account. The employer generally has no annual Form 5500 filing, and there is no ADP test.

A 401(k) is an ERISA plan. You adopt a written document, hire a recordkeeper, and file Form 5500 or the short Form 5500-SF each year. The Pew Charitable Trusts found that many providers charge Form 5500 prep fees of $250 to $750, and some charge about $1,500 when the document needs a restatement.

Salary-reduction deposits have a clock. The IRS says employee SIMPLE deferrals must reach the IRA within 30 days after the end of the month the pay would have been cash. Employer money is due by the tax-return due date, including extensions.

The investment menu is the quieter split. A SIMPLE IRA follows IRA rules at whatever firm holds the account. A 401(k) can build a lineup, allow loans if the document says so, and, in large plans, open the door to private assets into 401(k) menus. SIMPLE IRAs do not permit participant loans.

If the plan exists because staff expect one, and nobody is trying to max a high salary, that lighter file is the whole case for SIMPLE. The cost shows up when the owner’s own deferral cap becomes the constraint.

Immediate Vesting Hands Staff the Match on Day One

Every dollar that lands in a SIMPLE IRA is the employee’s as soon as it hits, including the employer piece. The IRS says SEP and SIMPLE IRA plans require that all contributions stay 100% vested.

A traditional 401(k) can hold back employer money. Elective deferrals are always 100% vested. Matching or profit-sharing amounts may follow a schedule no slower than a 3-year cliff or a 6-year grade. Safe harbor 401(k) and SIMPLE 401(k) contributions must vest at once, so the retention tool is a traditional 401(k) feature, not a safe harbor one.

THE SLOWEST 401(K) VESTING THE LAW ALLOWS

Walk through a 3-year cliff. A worker who leaves after two years keeps every personal deferral and forfeits the entire match. Under a SIMPLE IRA that same person walks with the match. If you are funding the plan partly to keep people, the extra 401(k) admin is the price of that lever.

The 100-Employee Ceiling and the One-Plan Rule

Only an employer that had no more than 100 employees with $5,000 or more in pay during the prior calendar year can set up a SIMPLE IRA. The IRS count includes people who have not yet met the plan’s eligibility tests. Eligibility itself is usually $5,000 in any two prior years and a reasonable expectation of $5,000 this year, unless you loosen that bar.

Cross 100, and you get a short fuse rather than an instant penalty. If you already had a SIMPLE IRA, you still meet the 100-employee test for the two calendar years after the year you last passed it. After that window, the plan no longer fits.

The one-plan rule is the conversion trap people miss. You generally cannot contribute to a SIMPLE IRA for a calendar year if you maintain another retirement plan and any employee gets an allocation or accrues a benefit under that other plan in the same year. Union-only plans and some acquisition cases are the narrow exceptions.

You also cannot layer a profit-sharing 401(k) on top of a live SIMPLE IRA to mop up extra owner room. The IRS treats the year of the allocation, not the year you deposit the check, as the year you “had” the other plan. A leftover prior-year profit-sharing deposit does not block a SIMPLE IRA this year. An overlapping non-calendar profit-sharing year does.

Switching Midyear Is Possible, With a Prorated Cap

Money already sitting in a SIMPLE IRA does not move like a 401(k) balance. During the two years after the employee first participated, a transfer to anything except another SIMPLE IRA is treated as a withdrawal.

During the 2-year period beginning when you first participated in your employer’s SIMPLE IRA plan, you can only transfer money to another SIMPLE IRA.

Internal Revenue Service, SIMPLE IRA withdrawal and transfer rules

Do it anyway, and the IRS says you include the amount in income and pay an extra 25% tax unless you are at least 59½ or another exception applies. After two years, a tax-free rollover to a non-Roth IRA or an employer plan is allowed, and a Roth rollover is a taxable conversion.

SECURE 2.0 softened the exit for the employer. For plan years beginning after December 31, 2023, you can replace a SIMPLE IRA during the year with a safe harbor 401(k), a SIMPLE 401(k), or a QACA. Plan administrators citing IRS Notice 2024-02 say the two-year rollover wait is waived when the new plan keeps 401(k) distribution limits, and that the year’s deferral cap is prorated by day across the two plans.

THE SIMPLE-TO-401(K) CALENDAR

1. October 1: Last day to make a first-time SIMPLE IRA effective for the current year, unless you are a new business formed after that date.
2. November 2: The 60-day employee election window generally opens for the next calendar year, and the employer notice of next year’s formula is due before it.
3. January 1: Clean replacement date if you stop the SIMPLE IRA at year-end and open the 401(k) for the new year.
4. Two calendar years after crossing 100 employees: Grace period on the 100-employee test ends, and the SIMPLE IRA no longer fits.

A midyear jump is the rushed version of that calendar, not a free upgrade. If the owner already deferred a large SIMPLE amount, leftover 401(k) deferral room for the same year shrinks on the proration. Employer 401(k) contributions can still use the $72,000 annual-additions cap, which is why some shops still make the move before December.

Owner-Heavy Shops Outgrow SIMPLE First

Run the 2026 math for a founder who takes $300,000 of pay at age 45. A standard SIMPLE IRA takes $17,000 of deferrals plus a 3% match of $9,000, or $26,000. The enhanced small-employer deferral lifts that to $18,100 plus the same $9,000 match, or $27,100. A 401(k) can take $24,500 of deferrals and enough employer profit sharing to reach the $72,000 annual-additions limit.

At 52, the catch-up widens it. SIMPLE adds $4,000. The 401(k) adds $8,000. From 60 through 63, the 401(k) super catch-up is $11,250 against $5,250 in a SIMPLE plan. For 2026, a 401(k) participant whose prior-year FICA wages from that employer topped the Roth catch-up wage threshold of $150,000 must put that catch-up in as Roth, which changes the tax mix but not the extra room.

A practice with one high earner and a few staff hits this wall first. The SIMPLE cap binds the person trying to shelter the most, while the required match still covers everyone who defers. Uneven cash flow makes the required check worse, because you cannot pause it.

A business of one is a different comparison. The IRS 2026 defined contribution limit of $72,000 is the same ceiling a SEP IRA or a solo 401(k) uses. Those designs usually beat both SIMPLE and a full staff 401(k) when there is no crew to cover. Advisors still flag the SIMPLE two-year lock when someone later wants to roll a balance into a 401(k) to clear IRA money for a Roth conversion, which is one more reason not to start there if a solo 401(k) was always the end state.

Choose SIMPLE if headcount is small, nobody is near the $17,000 cap, and you can live with a required yearly contribution and instant vesting. Start with a 401(k) if the owner already wants more than $18,100 of deferrals, if you want a vesting schedule on the match, or if you can see 100 employees from here. The cheap plan is cheap until the conversion file opens.

Frequently Asked Questions

Can I Have a SIMPLE IRA and a 401(k) in the Same Year?

Generally no for the same business, because the IRS one-plan rule blocks SIMPLE contributions in any calendar year that another plan allocates contributions or accrues a benefit for any employee. Two exceptions exist: a plan that covers only collectively bargained employees whom the SIMPLE IRA excludes, and certain acquisition or disposition groups during the current year or the prior two years. The test follows the year of the allocation, so a profit-sharing deposit made this year for last year’s plan year does not, by itself, bar a SIMPLE IRA this year.

Does a SIMPLE IRA Require Form 5500?

A SIMPLE IRA generally does not. The financial institution files Form 5498 for each IRA, and the employer checks the retirement-plan box on Form W-2. A SIMPLE 401(k), which is a different Code design, does file Form 5500 each year even though its contribution formulas look similar. One-participant 401(k) plans file Form 5500-EZ once year-end assets top $250,000, or in a final year.

What Happens if We Cross 100 Employees?

You keep the SIMPLE IRA through a two-year grace period after the last year you satisfied the 100-employee test, then you have to move. The IRS count is every employee who earned $5,000 or more at any time in the prior calendar year, including people who have not met the plan’s eligibility tests. Special rules apply if the jump comes from an acquisition or similar transaction, which is why growing firms often open a 401(k) before the count gets close.

Can I Roll a SIMPLE IRA Into a 401(k)?

After two years of participation, yes, if the 401(k) accepts incoming rollovers. Inside those two years, a shift to anything except another SIMPLE IRA is treated as a withdrawal, with income tax and a 25% extra tax unless you are 59½ or another exception applies, such as disability or an IRS levy. When an employer replaces the SIMPLE IRA with a 401(k) that keeps 401(k) distribution limits, SECURE 2.0 and IRS Notice 2024-02 waive that two-year wait for the rollover into the new plan.

Should a Business With No Employees Use Either Plan?

Usually neither. A SEP IRA and a solo 401(k) both use the 2026 defined contribution cap of $72,000, which is the same ceiling as a staff 401(k)’s annual additions, and they do not force a 3% match across a workforce you do not have. A solo 401(k) also lets the owner defer $24,500 plus catch-up as the employee, then add employer profit sharing, which is the structure a SIMPLE IRA cannot copy. Add a second employee who is not a spouse, and that solo design becomes an ordinary 401(k) with testing and filing.

Disclaimer: This article is news reporting and analysis of IRS plan rules and 2026 contribution limits, and it is for information only. It is not tax, investment, legal, or retirement-plan design advice, and it is not a recommendation to adopt, keep, or terminate a SIMPLE IRA or a 401(k). Speak with a certified public accountant, a tax attorney, or a fiduciary retirement-plan adviser who can review your payroll, ownership, and cash flow before you sign a plan document or change an existing one. Dollar figures, eligibility tests, and filing duties reflect the IRS, FINRA, and research sources cited here as of September 1, 2026, and Congress and the IRS can change them.