S-Corp Election Deadline for 2026

The rule is two months and fifteen days after the tax year begins. For calendar year filers that normally lands on March 15.

March 15, 2026 fell on a Sunday, which pushed the deadline forward. The operative date became Monday, March 16, 2026.

Entities formed mid year follow a different clock entirely. Their deadlines run from the first day of their first tax year.

Form 2553 must arrive within two months and fifteen days of the year start. That measurement is not the same as seventy five days. The two month period ends the day before the numerically corresponding date. Fifteen days are then added to reach the final deadline.

For a calendar year, the two month period ends February 28. Adding fifteen days produces March 15 in an ordinary year. Because that date fell on a Sunday in 2026, the deadline shifted. Filings due on weekends or legal holidays move to the next business day.

That shift is a general rule, not a special accommodation. Federal holidays that affect filing dates are posted annually by the personnel office. The underlying two month and fifteen day rule is stated there in the form instructions. Nothing about the 2026 shift changed the substance of the rule.

Looking ahead, the picture is simpler. An election effective January 1, 2027 may be filed any time during 2026. It may also be filed through Monday, March 15, 2027. That date falls on a weekday, so no shift applies.

A new entity does not use the March date at all. Its first tax year begins on the earliest of three events. Those are issuing stock, acquiring assets, or beginning business operations. Registering with a state agency does not by itself start the clock.

From that starting date, the same two month and fifteen day rule applies. An entity that began operations on January 10 faced a March 24 deadline. One that started June 1 faced August 15, which fell on a Saturday. That deadline moved to Monday, August 17, 2026.

Entities forming later in 2026 still have open windows. A business beginning operations on September 1 has until November 16. Owners in that position should file now rather than waiting. Nothing is gained by holding the form until the deadline approaches.

The table below applies the rule to common 2026 starting dates. Two of the listed deadlines shifted because they landed on weekends. The final row is the one most readers can still act on today. Everything above it now requires the relief procedure.

Two of these dates deserve a second look. The March and August deadlines both moved because of weekend placement. The November and March 2027 dates required no adjustment. Always check the calendar rather than assuming the fifteenth.

Missing the date does not permanently cost you the election. It shifts you from an automatic filing into a relief request. The governing procedure allows relief within three years and seventy five days. That window measures from the intended effective date, not from today.

For a January 1, 2026 effective date, relief remains available into 2029. The entity must have intended S treatment from that date forward. It must have failed to qualify solely because the form was late. It must also have reasonable cause and act with reasonable diligence.

The consistency requirement is what actually defeats most requests. Every affected return must already reflect S corporation treatment. A filed Schedule C or partnership return contradicts the entire premise. Amend those returns before submitting the relief request.

Consequences of ignoring the problem compound quickly. The entity remains a disregarded entity or partnership for 2026. Self employment tax applies to all profit for that year. Late return penalties are covered by others in current practitioner guidance.

Acting quickly matters, because delay itself weakens a relief request. Work through the sequence below before filing anything. Each step closes a gap the IRS will otherwise question. The order is deliberate rather than arbitrary.

• Confirm the intended effective date and count the relief window from it
• Verify no filed return contradicts S corporation treatment for that year
• Amend any return that reports the income on a different basis
• Draft a factual reasonable cause statement with specific dates
• Complete Part IV of Form 2553 and gather every shareholder signature
• Write the required procedure reference at the top of the form
• File the form independently or attach it to the delinquent return

One decision point catches owners who missed 2026 entirely. You may pursue retroactive relief to January 1, 2026. You may instead elect prospectively for January 1, 2027. Compare the tax savings against the cost of amending prior returns.

The 2026 deadline for calendar year entities was Monday, March 16. The weekend shift moved it from the usual fifteenth. Entities formed during 2026 measure from their own first day instead. Several of those windows remain open through late autumn.

If you missed it, relief runs three years and seventy five days from the intended date. Fix your returns first, because consistency governs the outcome. Write a statement with dates rather than adjectives. And if retroactive relief is not worth the cleanup, file now for January 1, 2027.