2027 Maine Tax Deadlines

Last updated: July 29, 2026

Key Maine tax dates at a glance

• April 15, 2027: First Individual estimated payment.
• June 15, 2027: Second Individual estimated payment.
• September 15, 2027: Third Individual estimated payment.
• January 18, 2028: Fourth Individual estimated payment.
• March 15, 2028: Form 941P-ME pass-through withholding and composite return when required.
• April 18, 2028: Calendar-year Form 1120ME and Individual returns and payments.
• September 15, 2028: Extended Form 941P-ME, file only.
• October 16, 2028: Extended Form 1120ME and Individual returns, file only.

When are Maine taxes due in 2027?

Maine 2027 calendar-year C Corporation and Individual returns are generally due April 18, 2028. When Form 941P-ME applies, the pass-through withholding and composite filing deadline is March 15, 2028.

When is the Maine C Corporation return due?

Maine C Corporations should plan around April 18, 2028 for the calendar-year corporate-facing return, tax, or business-level filing noted on this page.

• Form 1120ME: Maine corporate income tax return.

What are Maine C Corporation extension rules?

The extended filing deadline for the Maine calendar-year corporate-facing return is October 16, 2028. The extension is to file only, and tax or required payments remain due by April 18, 2028.

When are Maine S Corporation and Partnership returns due?

Maine S Corporations should plan around March 15, 2028, when Form 941P-ME applies, and Partnerships should plan around March 15, 2028, when Form 941P-ME applies.

Which Maine pass-through forms are required?

Use the applicable Maine pass-through return and related payment or owner-reporting forms for the entity type and election facts.

• Form 941P-ME: Pass-through withholding and composite filing for entities with Maine-source income and nonresident members.
• Schedule 3P: Member reporting with Form 941P-ME when required.

What are Maine pass-through extension rules?

The extended filing deadline for calendar-year Maine S Corporation and Partnership returns is September 15, 2028, when Form 941P-ME applies. The extension is to file only, so tax, withholding, composite, or entity-level payments should be handled by the original deadline.

When is the Maine Individual income tax return due?

Calendar-year Maine Individual income tax returns and payments are due April 18, 2028.

• Form 1040ME: Resident Individual income tax return.
• Schedule NR or Schedule NRH: Nonresident or part-year resident allocation when applicable.
• Form 1040ES-ME: Individual estimated tax vouchers.

What Maine Individual rate and residency issues should be checked?

Tax year 2027 Individual instructions should be checked for final rate tables, standard deductions or exemptions, residency rules, retirement-income treatment, credits, estimated-payment thresholds, and any filing-year changes specific to Maine.

When are Maine estimated payments due?

Maine estimated-payment planning should separate Individual estimates from the Form 941P-ME $1,000 estimated composite-liability threshold.

• April 15, 2027: First estimated payment.
• June 15, 2027: Second estimated payment.
• September 15, 2027: Third estimated payment.
• January 18, 2028: Fourth estimated payment.

Who must make Maine estimated payments?

Taxpayers should use the final 2027 Maine instructions to confirm estimated-payment thresholds, safe-harbor rules, credits, withholding, pass-through owner treatment, and electronic-payment requirements.

What are Maine extension deadlines?

Maine extension deadlines are September 15, 2028, when Form 941P-ME applies for pass-through filings, October 16, 2028, for corporate-facing filings, and October 16, 2028, for Individual returns. Extensions add filing time only; payment deadlines remain tied to the original return due dates.

What Maine-specific rules should tax professionals watch for 2027?

Beyond the core return deadlines, Maine tax professionals should track state-specific rate, credit, local-tax, industry, and filing-method rules before the 2027 season locks.

• Maine's current Individual income tax schedule uses rates from 5.8% to 7.15%, and tax-year 2027 bracket thresholds should be reconfirmed when published.
• Maine does not require a general Partnership or S Corporation income return.
• An S Corporation or Partnership with Maine-source income and nonresident members may need Form 941P-ME, withholding, composite reporting, and Schedule 3P member schedules.
• Form 941P-ME is not required when all members are Maine residents, but an S Corporation with entity-level taxable items such as built-in gains may need Form 1120ME.
• Use Maine Tax Portal to file, pay, manage notices, and verify account activity, and confirm mandatory electronic filing for each return type.
• Review Maine additions, subtractions, credits, nonresident allocation, and conformity updates rather than carrying federal taxable income forward without adjustment.
• Review Maine's progressive rate schedule with respect to property, sales, and use-tax exposure.
• Forestry, timber, natural-resource, fishing, seafood, aquaculture, lodging, meals, short-term rental, and seasonal tourism businesses may face specialized tax, license, sourcing, and local-registration obligations.
• Pine Tree Development Zones and research, employment, investment, renewable-energy, efficiency, conservation, and environmental programs require eligibility and benefit-period review.
• Maine allows certain pension deductions and special treatment for Social Security and military retirement income.

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Teams comparing Instead tax software with spreadsheet trackers should keep return type, payment status, extension status, and source-backed state rules together. Use Instead tax AI as a review surface for deadline orchestration, while AI tax software and tax advisor AI prompts support professional judgment rather than replacing state-source review.

What sources support these Maine dates?

Use these official or primary Maine tax sources to confirm the return, payment, extension, and state-specific rules above before publication.

• Maine corporate income tax forms.
• Maine Individual income tax forms.
• Maine pass-through entity withholding guidance.
• Maine Tax Portal.

Turn Maine's mixed filing rules into one calendar

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For Maine practices, estimates, planning, and family offices, it helps connect research, planning, and operational handoffs without duplicating deadline data. Built for tax professionals who want source-backed state deadline control across clients, entities, and reviewer workflows.