Maine tax deadlines in 2026: filing dates and estimated payments
Deadlines that fall in calendar 2026: the 2025 return and the 2026 estimated payments. Different year? See Maine 2025 →
Maine deadlines in 2026
| 2025 individual return due | April 15, 2026 |
|---|---|
| Extended filing deadline | October 15, 2026 |
| Payment due | April 15, 2026, extension or not |
| Final 2025 estimated payment | January 15, 2026 |
| 2026 estimated payments | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Conforms to April 15. Patriots' Day (3rd Monday of April, a Maine holiday) pushes the deadline in some years; for the 2025 tax year (filed 2026) it remains April 15. Automatic 6-month extension if 90% of tax is paid.
Maine estimated tax payments in 2026
You must pay estimated tax if your estimated Maine income tax for the year, over and above tax withheld and allowable credits, is $1,000 or more and your tax liability for the prior year was also $1,000 or more.
| Q1 (2026 tax year) | April 15, 2026 |
|---|---|
| Q2 (2026 tax year) | June 15, 2026 |
| Q3 (2026 tax year) | September 15, 2026 |
| Q4 (2026 tax year) | January 15, 2027 |
| Voucher | Form 1040ES-ME |
| Underpayment safe harbor | No underpayment penalty if each installment is paid on time and total estimated tax paid equals 90% (66 2/3% for farmers and fishermen) of the current-year tax or 100% of the prior-year tax when that year was a 12-month year. |
| Pay online | revenue.maine.gov |
Farmers and fishermen (at least two-thirds of estimated AGI from farming or fishing) may pay a single installment by January 15, 2027, or skip estimates by filing the 2026 return and paying in full by March 1, 2027. For tax years beginning in 2026 a 2% surcharge applies to Maine taxable income above $1,000,000 for single filers.
Source: maine.gov, read September 3, 2026. “You may either pay all of your estimated tax at that time or pay in four equal installments on April 15, 2026, June 15, 2026, September 15, 2026, and January 15, 2027.”
All 51 jurisdictions in one table: state estimated tax payment dates for 2026.
Maine extensions
Every state's rule in one table: which states accept the federal extension in 2026.
| Does Maine accept the federal extension? | Not needed. The state extends everyone automatically. |
|---|---|
| Original due date | April 15, 2026 |
| Extended due date | October 15, 2026 |
| Payment | Still due April 15, 2026. The extension is to file, not to pay. To avoid late-payment penalties you must pay at least 90 percent of the tax owed by the original due date; interest accrues on unpaid tax. |
| How to get it | Nothing to file; pay any estimated tax via the Maine Tax Portal or the extension payment voucher by April 15. |
Maine's FAQ also notes the automatic extension equals the federal extension or six months, whichever is later; total extension cannot exceed eight months.
Source: maine.gov, read September 3, 2026. “If you are unable to file your return by the original due date, Maine will allow an automatic six-month extension of time in which to file your return.”
Federal deadlines in 2026
| 2025 Form 1040 | April 15, 2026 · extension October 15, 2026 |
|---|---|
| 2025 S-corp (1120-S) & partnership (1065) | March 16, 2026 |
| 2025 C-corp (Form 1120) | April 15, 2026 |
| 2026 federal estimated payments (1040-ES) | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Source: IRS Publication 509 and Form 1040-ES instructions, irs.gov.
Frequently asked questions
When are Maine state taxes due in 2026?
Your 2025 Maine individual income tax return is due April 15, 2026. If that date falls on a weekend or legal holiday, the deadline moves to the next business day. An extension moves the filing deadline to October 15, 2026, but any tax owed is still due on the original date.
When are Maine estimated tax payments due in 2026?
Maine estimated payments for the 2026 tax year are due April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027. Use Form 1040ES-ME or pay online. The final installment for 2025 was due January 15, 2026.
Does Maine accept the federal extension?
Not needed. The state extends everyone automatically. The extended filing deadline is October 15, 2026, and tax is still due by April 15, 2026.
Does a Maine extension give me more time to pay?
No. An extension extends the time to file, not to pay. To avoid penalties and interest, pay what you expect to owe by April 15, 2026.
Dates are the statutory deadlines that fall in 2026 and move to the next business day when they land on a weekend or holiday. Each section links to the source it was checked against. Always confirm with the Maine tax agency or the IRS before relying on a date. This is general information, not tax advice.