The 2025 deduction may still be open. Funding is a different clock.

Today is March 1, 2026. The 2025 plan year has been over for two months. For many owners it still feels unfinished, because the tax return is unfinished. That feeling is partly right. If the employer's return for 2025 is extended, the contribution that will be deducted on that return can often still be deposited, and the deduction is not dead. The feeling is also how minimum funding gets missed. The funding statute does not care that the accountant is on extension. A calendar-year defined benefit plan generally owes its minimum required contribution by September 15, 2026. An S corporation that files on time may owe the deduction problem in two weeks and the funding problem in September. Those are not two ways of saying the same date.

Sterling Pension Group is a third-party administrator. We are not an actuarial firm, and we are not your CPA. An independent Enrolled Actuary certifies the minimum and the deductible maximum. The CPA decides what the return can claim. This briefing is not tax, legal, or actuarial advice. It is a separation of the 2025 file, which is still open for many readers, from the 2026 year, which has already been running for sixty days.

Which returns are about to be due, and which are not

A partnership or an S corporation on a calendar year generally files by March 15, 2026. That date is fourteen days from today. If March 15 falls in a way that pushes the legal due date to the next business day, the CPA will apply that rule. Do not invent the shift yourself, and do not ignore the week because you have heard extensions are automatic. An extension is a filing. It is Form 7004 for these entities, and it has to be submitted on time. A partnership or S corporation that extends generally has until September 15, 2026 to file. A sole proprietor, and many calendar-year C corporations, are on a different original date, generally April 15, 2026, with an extension that commonly runs to October 15, 2026. If you do not know which taxpayer sponsors the plan, you do not know which of these sentences is yours. The sponsor is the employer. A shareholder's personal Form 1040 is not the S corporation's deadline. A partner's personal return is not the partnership's deadline.

The deduction rule owners are relying on is the one that treats a payment made after year-end, and by the due date of the return including extensions, as if it had been made on the last day of the year, when the payment is on account of that year. The payment has to reach the plan's trust. A payable on the books is not a payment. The amount has to be within the deductible maximum the actuary determines for 2025. It has to be a contribution for the 2025 year, not a 2026 credit that was deposited early and mislabeled. Publication 560 is the IRS publication to read beside the CPA's instructions so the word "on time" has a public meaning. The publication will not know whether you extended.

If you intend to file the S corporation or partnership return on the original date, the contribution you want to deduct for 2025 generally has to be in the trust before you file, and in any event by that original due date. Two weeks is enough time to wire an amount you already know. It is not enough time to design a plan, obtain a valuation, open a trust, and adopt a formula you have not started. The rule that can treat a plan as adopted on the last day of the prior year, if it is adopted by the filing deadline including extensions, still does not let design start on the deadline. If the census, the document, and the actuary are not already in motion, do not promise the CPA a 2025 pension deduction during the week of March 15. Use the extension, if you are going to use one, to finish a file that was already real — or admit that 2025 was the year you decided, and 2026 is the year the plan will cover.

The funding clock did not move with the extension

Minimum funding for the 2025 plan year of a calendar-year defined benefit plan is generally due September 15, 2026. That date is 8.5 months after the plan year ended. It comes from the funding rules, not from the income-tax return. Extending an S corporation to September 15 makes the extended filing date and the typical funding date land on the same day. They are still different jobs. Extending a sole proprietor to October 15 makes the deduction deadline later than the funding deadline. In that pattern you can still owe an excise tax for an unpaid minimum even though the CPA is willing to wait another month for the deduction. The excise tax on an unpaid minimum required contribution starts at 10 percent. A further tax applies if the shortfall is not corrected in the taxable period. Neither tax is canceled by a valid extension.

Some plans owe quarterly contributions before the September 15 outside date. The quarterlies depend on whether the plan has a funding shortfall as the actuary measures it. A small cash balance plan is sometimes able to satisfy the minimum with one payment by the outside date. Sometimes it is not. The Schedule SB and the actuary's funding notice are the documents that say so. If you have never seen them for 2025, ask now, not in August. A quarterly that was due in 2025 and was missed is not repaired by a March extension of the income-tax return.

None of this is Form 5500. The annual return for a 2025 calendar-year plan is generally due July 31, 2026, and it can be extended to October 15, 2026 on Form 5558. The IRS Form 5500 corner explains the return. The Department of Labor's filing page is the compliance home for actually filing it. An extension of Form 5500 does not extend minimum funding. An extension of the income-tax return does not file Form 5500. Owners who keep one reminder called "pension due in the fall" will satisfy whichever deadline they happen to remember and miss another. The deadline calendar is only useful if it has separate lines. Plan administration through the spring is mostly keeping those lines from collapsing into a single wire.

PBGC premiums, if the plan is covered, are yet another line. Coverage is plan-specific. A plan of a professional-service employer with 25 or fewer active participants may be exempt. A plan that covers only substantial owners may be exempt. A plan that fits neither category does not become exempt because the sponsor extended a tax return. The coverage guidance is the map. If your 2025 file still says "PBGC to be determined," determine it before a premium form is the way you find out.

Use 2025 limits on the 2025 deposit

A contribution deposited in March 2026, or in September 2026, and deducted on the 2025 return, is governed by the 2025 limits if it is a 2025 contribution. The elective deferral limit for that year was $23,500. The ordinary catch-up was $7,500. Ages 60 through 63 were $11,250. The defined contribution annual-additions limit was $70,000. The compensation cap was $350,000. The defined benefit dollar limit was $280,000. The IRA limit was $7,000. The release is IR-2024-285. The actuary's 2025 certification should cite those figures. If a draft uses the 2026 benefit limit of $290,000 or the 2026 compensation cap of $360,000 on a 2025 schedule, it is the wrong year.

The 2026 limits are in force for 2026. Deferrals $24,500. Ordinary catch-up $8,000. Ages 60 through 63 still $11,250. Annual additions $72,000. Compensation cap $360,000. Defined benefit dollar limit $290,000. IRA limit $7,500, with an IRA catch-up of $1,100. They were announced in IR-2025-111 and Notice 2025-67, effective January 1, 2026. They belong on the 2026 valuation and on 2026 payroll. They do not enlarge a 2025 deduction because you are writing the check in 2026. The side-by-side table is the IRS COLA page. Print it and mark the column with the year of the return you are filing. The limits notes you keep internally should do the same.

The defined benefit figure, in either year, is not the size of the check. The IRS states the $280,000 and $290,000 limits as limits on the annual benefit. The explanation is on the benefit limits page. The check is whatever the Enrolled Actuary certifies as the minimum, and whatever the CPA is willing to deduct up to the maximum, given the document and the deposit date. An illustrative number generated last fall does not become certifiable because the extension gave you more time. If the final census changed the picture — a bonus, a hire, a termination, compensation under the cap — the illustration is stale. Ask for the updated range before the CPA locks a figure on an extension worksheet.

Roth catch-up does not rewrite the 2025 deposit either. The mandatory Roth treatment of catch-up contributions, for participants with prior-year FICA wages over $150,000, became operational on January 1, 2026. It affects 2026 catch-up deferrals in the 401(k). It does not recharacterize a 2025 catch-up that was properly pre-tax. It does not touch a cash balance pay credit for either year. If a 2026 payroll report and a 2025 pension wire are in the same folder this week, keep them in different folders.

What the CPA still needs, even though the year is over

The census for 2025 can now be final. Send it final: compensation actually paid, hours, entry and exit dates, ownership, related employers. Send proof of any deposit already made, with the trust account identified. Send the adoption documents and the date of adoption. Send the actuary's minimum and maximum when they exist, and do not send an illustrative figure in their place. Send a statement of whether the return will be extended. The CPA cannot accrue a number you intend to fund in September if you have also told them you might file in two weeks without funding. Pick a path.

Entity still matters in March as much as it mattered in October. The deduction belongs on the employer's return. A personal estimated-tax payment is not a pension contribution. A transfer from a shareholder to an S corporation, so the corporation can contribute, may be a capital contribution or a loan. The CPA has to characterize that transfer. It is not automatically the deduction. Partnership allocations of the contribution follow the partnership agreement. A partner who wants the entire pension deduction allocated to one partner, because that partner is the oldest, needs the agreement and the testing to support the allocation. Age does not allocate a partnership deduction by itself.

If both a defined benefit plan and a defined contribution plan covered the same employees in 2025, the deductible maximum is not the sum of the two plans' separate ceilings. The combined-plan deduction rule may apply, and PBGC coverage may change the analysis. The $70,000 annual-additions limit of 2025 is not a pension limit. Catch-up contributions of $7,500 or $11,250 sat outside annual additions and should be identified so they are not mistaken for employer money. Fees for actuarial work and administration are not the contribution. Ask the CPA how those invoices are deducted. Do not add them to the wire and call the total the pension deposit.

2026 has its own file, and March is not too early to keep it from contaminating 2025. Pay credits accruing now use 2026 compensation and the 2026 limits. A soft first quarter may justify a prospective amendment or a lower declaration inside a written range. It does not justify relabeling a 2026 reduction as a 2025 deduction strategy. The cash balance formula for the current year and the certification for the prior year should be in different emails if that is what it takes to keep the years straight. Self-employed owners with a single bank account feel this confusion most, because there is no corporate cash account to make the employer status obvious. The law still sees an employer plan. The wire should too.

What to do in the next two weeks

Decide the extension before the original due date decides you. If you are an S corporation or a partnership and the 2025 pension number is not final, extending is often the correct administrative act. File the extension. Do not treat the extension as a funding waiver. Ask the Enrolled Actuary for the 2025 minimum and the 2025 maximum on the final census, under the 2025 limits, in writing. Schedule the deposit that satisfies at least the minimum by September 15, 2026, and schedule a separate reminder for the deduction deposit by whatever date the return you intend to file actually requires.

If a 2026 credit needs to come down because the year is soft, start that amendment or declaration on its own track, with 204(h) notice if the reduction is significant. Do not wait until the 2025 return is filed to mention it. Send the CPA package and the funding date in one note so the coordinator, the actuary, and the CPA are looking at the same year labels. Two weeks from today is March 15. For many readers that morning is an original due date. The briefing that belongs on that morning is about the two clocks landing on the same season, and about not pretending they are one clock.