SIMPLE IRA Deadline: When to Set Up and Fund Your Plan (2026)

An existing business has to create a new SIMPLE plan by October 1 of the current year in order to have contributions counted for this tax year. If you miss this date you will be unable to make any contributions until the start of next year. Once a SIMPLE Plan has been established, all employee deferrals must be deposited into the custodian within 7 business days from each payroll and your match or 2% (nonelective) contribution is due as of your business tax filing deadline, which includes extensions on the filing deadline. A SIMPLE IRA plan uses three different clocks, and these clocks operate at vastly different rates.

The setup deadline is the one that most owners get wrong because of a common misconception that the end-of-year planning process should also have a year-end deadline. It doesn't.

What is the SIMPLE IRA deadline?

The time frame includes three different due dates that create confusion among employers each Fall. 1) The setup deadline is when an existing employer will be required to establish a new SIMPLE IRA on or before October 1 of the same calendar year in order for it to have been established for the current calendar year. However, the IRS provides a window for effective date from January 1 through October 1 of the current calendar year provided you have not previously maintained a plan. However, there is one exception, if your company was newly formed after October 1.^[1] 2) The second is that you must make deposits into your employees' accounts within seven (7) business days of each payday. 3) Finally, an employer's contributions can be made at their extended tax filing deadline. If you are still trying to determine whether this type of plan would fit with your goals and objectives, begin with what a SIMPLE IRA is.

Can you set up a SIMPLE IRA any time before year-end?

No, and this is the myth that results in a one year loss of tax deferred savings for the owner. It is easy to believe a new SIMPLE IRA will work similarly to making an IRA contribution up until April, but it doesn't. A current business has to establish the plan by October 1, therefore if you decide in November, your earliest date to have it start is January 1 of next year. There is an October 1 deadline so employees receive their full 60 day election window prior to when the first plan year begins, and this notice isn't optional either. Pursuant to 26 U.S.C. 6693(c), if there are failures regarding providing a SIMPLE notice to all eligible employees, the failure penalty of $50 per day, per failure shall be imposed unless there was reasonable cause.^[2] Sign by September 20 and staff can defer this year. Sign on November 10 and an entire year of deferrals will be lost.

How do you set up a SIMPLE IRA?

Creating a SIMPLE IRA is a short process, and you do not have to submit anything to the IRS. You complete a model form (Form 5304-SIMPLE and 5305-SIMPLE) which will allow you to decide whether your employees can choose from any custodian or if you will select a single custodian for all of your employees. Once completed, sign the form by October 1 to establish the plan and keep the signed original in your records.^[3] If your company was formed after October 1, set up the plan as soon as administratively feasible.^[4] Give the 60-day notice to all employees before the November 2 to December 31 election window. Employees will open their individual SIMPLE IRA accounts, and after payroll withholds deferrals, remit them within seven business days of when they were withheld.

When is the SIMPLE IRA contribution deadline?

Two funding clocks replace the one setup deadline when you have a plan established. The fast clock is employee contributions (deposits). The DOL rule at 29 CFR 2510.3-102 requires withheld deferrals to get to the plan as soon as they can reasonably be segregated from your general assets, and this same DOL regulation provides a "safe harbor" for plans that have fewer than 100 participants. This safe harbor states that a deposit will be considered on time if it arrives before the end of the seventh business day following the pay date.^[5] The outside legal limit is thirty days after the month in which withholdings occur, however, the seven-business-day safe harbor is the number to run against. The slow clock is employer contributions. IRS Publication 560 states that employer contributions are due no later than the due date of your business income tax return, including any extension of such filing period.^[6] A 2026 match may legally be funded in 2027. An employer's compliance calendar includes deposit and notice rules at its core.

What does the SIMPLE IRA deadline calendar look like?

A calendar year SIMPLE IRA, once started, follows a fairly predictable annual cycle of events. Setup is pinned to October 1, and then the same dates recur each year. You will send out a fall notice to employees, and then the election window runs in winter. Finally the employer will make payroll deposits into employee accounts, as well as handle W-2 reporting. In that fall notice you also announce the dollar caps for the next year, i.e., your 2026 contribution limits. Below are the specific dates that repeat annually:

There's only one day with no second chance, October 1. You can correct a missed notice or an untimely deposit through either the Department of Labor or the IRS correction program. However, if you miss that "setup wall," there will be no plan for the entire year.

The Bottom Line

You have three deadlines for your SIMPLE IRA. An October 1 deadline for an existing business to start its SIMPLE IRA plan in order to be eligible to make a retirement plan contribution for the current year, the seven-business-day deadline after each payroll date to deposit employees' contributions into their accounts, and, lastly, by your extended tax deadline you will need to fund the employer contribution. The one without forgiveness is October 1. It is best that when you are near this deadline, sign the plan document first and then send out the notice, as well as set up the account(s).

This guide is educational and summarizes IRS rules for SIMPLE IRA deadlines. It is not investment, legal, or tax advice. Your plan documents and current IRS limits control. Talk to your tax advisor about your business's circumstances.