Maine Estimated Tax Payments 2026: 1040ES-ME Due Dates, the $1,000 Rule, the 90%/100% Safe Harbor, and the Penalty Rate

Maine estimated tax payments for 2026 are due April 15, June 15, September 15, 2026, and January 15, 2027, and they are required when your 2026 Maine income tax after withholding and credits will be $1,000 or more and your 2025 Maine tax was also $1,000 or more. The first three dates have passed. The January 15, 2027 installment is still open, paid through the Maine Tax Portal or with a Form 1040ES-ME voucher, and the amount that protects you is the smaller of 90% of your 2026 tax or 100% of your 2025 tax.

Key takeaways:

• 2026 vouchers are due April 15, June 15, September 15, 2026, and January 15, 2027; filing your return and paying in full by January 31, 2027 cancels the penalty on the fourth one
• Maine's trigger has two parts: $1,000 or more of 2026 tax after withholding and credits, and a 2025 liability of $1,000 or more
• Safe harbor is the smaller of 90% of 2026 tax or 100% of 2025 tax, with no 110% tier; farmers and fishermen use 66⅔%
• 2026 rates stay at 5.8%, 6.75%, and 7.15%, but a new 2% surcharge applies to taxable income above $1 million ($1.5 million joint), enacted in April 2026
• The underpayment penalty runs at the MRS interest rate, compounded monthly: 9% for 2026 and 8% for 2027

Save this cheat sheet — Maine's 2026 numbers in one image.

When Are Maine Estimated Tax Payments Due in 2026?

Maine Revenue Services (MRS) collects estimated tax on the federal calendar, per the 2026 Form 1040ES-ME instructions, revised July 2026:

You may also pay the whole year with the first voucher; a weekend or holiday due date moves to the next business day. The dates mirror federal Form 1040-ES, so the estimated tax due-dates page covers both governments at once.

The January voucher has an exit. Under 36 M.R.S. § 5228(9), added in 2025, MRS charges no penalty on the fourth installment if you file your 2026 Form 1040ME and pay the tax in full by January 31, 2027. It suits people whose records are ready in January; anyone waiting on a K-1 should plan on January 15.

For 2027 the schedule repeats: April 15, June 15, and September 15, 2027, then January 18, 2028, because January 15, 2028 is a Saturday and January 17 is Martin Luther King Jr. Day, a Maine state holiday.

Who Must Pay Maine Estimated Taxes? The Two-Part $1,000 Test

You must make Maine estimated payments if your estimated 2026 Maine income tax, over and above withholding and allowable credits, is $1,000 or more and your 2025 tax liability was also $1,000 or more. The second half of that test is what sets Maine apart. Many states look only at the current year; Maine also asks whether you owed real tax last year, measured as total 2025 liability, not the balance left after withholding.

That prior-year condition protects people whose Maine tax was small in 2025. A graduate who started freelancing in 2026, or someone who moved to Maine in 2026 and owed under $1,000 to MRS for 2025, is outside the requirement for 2026 even with a large 2026 balance. A W-2 employee whose 2025 tax was fully withheld does not qualify if that 2025 liability was $1,000 or more. Form 2210ME mirrors the rule: no penalty if your 2025 liability was under $1,000.

The usual payers are self-employed people, pass-through owners, landlords, investors with gains, and retirees whose withdrawals exceed Maine's pension deduction. If your income changes mid-year, you can start late: pay the estimate on the next due date or spread it over the dates that remain.

The unusual event income rule

Maine has a special rule for one-time windfalls. If the Maine taxable income you receive in an installment period, other than wages subject to withholding, exceeds what you received in the same period of 2025 by $500,000 or more, the excess is "unusual event income." You must pay 90% of the tax on it for that installment, and the 100%-of-last-year option does not cover it. A business sale or a large capital gain is the typical trigger. Pass-through owners who had no control over the distribution and did not receive the cash can request an extension or penalty waiver in writing.

Maine Income Tax Rates for 2026 and What Changes in 2027

Maine keeps three brackets for 2026, indexed for inflation, per the 2026 rate schedules revised May 20, 2026:

The 2026 supplemental budget (LD 2212, Public Law 2025, chapter 650), enacted in April 2026, added a 2% surcharge on Maine taxable income above $1,000,000 (single), $750,000 (married filing separately), or $1,500,000 (joint and head of household). Maine's 2026 standard deduction is $15,700 single, $23,550 head of household, and $31,400 joint, below the federal 2026 amounts. MRS reissued the 1040ES-ME in July 2026 for both changes, so an estimate built on the spring worksheet may be off.

For 2027, two changes are already law: the surcharge thresholds will be adjusted for inflation, and the Maine standard deduction will equal the federal standard deduction, subject to Maine's phase-out, per the MRS 2026 tax law update.

Silas, a furniture maker in Portland, files single and expects $79,600 of 2026 federal adjusted gross income after the deductible half of self-employment tax, with no Maine modifications:

The Maine quarterly tax calculator repeats this math with your numbers and adds the federal side.

Maine Safe Harbor: 90% of 2026 or 100% of 2025

MRS charges no underpayment penalty when each required installment was paid on time and the total equals the smaller of these, per the 1040ES-ME and Form 2210ME:

Maine never asks for 110%, at any income. Silas's 2025 Maine tax was $3,200. His options are 90% × $3,695 = $3,325.50 or 100% × $3,200 = $3,200, so the prior-year number wins: four vouchers of $800, and the remaining $495 goes with his 2026 return in April with no penalty, however 2026 ends.

Size Your January 15 Voucher

When the safe harbor does NOT protect you

• One big January payment. Form 2210ME scores each installment separately, so a single catch-up on January 15 still leaves April, June, and September short for the months they sat unpaid
• A partial month. The penalty counts a part of a month as a whole month; paying September's voucher on September 16 costs a full month of penalty
• Your 2025 return was a short year. A short tax year forces you onto the 90% test
• A windfall quarter. Unusual event income above the $500,000 jump needs 90% of its own tax in that quarter, whatever you paid last year

How to Pay Maine Estimated Taxes Online or by Mail

The fastest route is the Maine Tax Portal (MTP) at revenue.maine.gov, where an electronic estimated payment replaces the voucher entirely. The 1040ES-ME notes that taxpayers with large liabilities must pay electronically, and MRS Rule 102 sets that line at a combined annual liability of $10,000 or more for all Maine taxes, per the August 2026 Maine Tax Alert.

To pay by mail, detach the 2026 Form 1040ES-ME voucher 4, check the box if you are a first-time estimate filer, and send it with a check or money order payable to Treasurer, State of Maine to:

Maine Revenue Services P.O. Box 9101 Augusta, ME 04332-9101

Joint filers list both spouses on the voucher. If you applied part of a 2025 overpayment to 2026 estimates, MRS lets you apply it to any installment.

Maine Underpayment Penalty: Form 2210ME and the 9% and 8% Rates

Maine's estimated tax penalty is interest by another name: the MRS FAQ says it runs at the same rate as interest on late payments, compounded monthly. The MRS interest-rate table sets that rate at 9% for 2026 (0.75% a month) and 8% for 2027 (about 0.67% a month). Form 2210ME computes it per installment from the due date until you pay, or until April 15, 2027 if earlier, and a part of a month counts as a whole one. For comparison, the IRS charges 7% for the fourth quarter of 2026 on the federal side, computed on Form 2210.

Suppose Silas skipped his $800 September 15 voucher:

Missing all three 2026 vouchers and catching up with one $2,400 payment on January 15, 2027 would cost about $121, the largest share from the April voucher's nine months. The fourth installment carries no penalty at all if he files and pays in full by January 31.

You do not have to file Form 2210ME when 2026 tax minus credits and withholding is under $1,000, or when your 2025 liability was under $1,000. If you used the annualized method for uneven income, file the form even when the penalty is zero.

When Maine Estimated Payments Do NOT Apply

• Low prior-year tax. A 2025 Maine liability under $1,000 takes you out of the 2026 requirement and the penalty
• Withholding-only years. If Maine withholding already covers the smaller safe harbor, no vouchers are needed
• Farmers and fishermen. With two-thirds of estimated AGI from farming or fishing, you can make one payment by January 15, 2027, or skip estimates by filing and paying in full by March 1, 2027
• Early filers. Filing and paying everything by January 31, 2027 removes the fourth-installment penalty

Maine-Specific Traps: Pensions, PTET, and the Surcharge

Pension income deduction

Maine lets each spouse deduct eligible pension and retirement income up to $49,824 for 2026, reduced by Social Security and railroad retirement benefits received, while military retirement pay is fully exempt. A retiree with no Maine withholding can still cross the $1,000 line once income exceeds the deduction.

The new pass-through entity tax

For 2026, Maine created an elective pass-through entity tax (PTET). An electing partnership or S corporation pays 7.15% at the entity level, and each member claims a refundable credit equal to 90% of their share on the 1040ME, per the MRS PTET briefing. Entity estimates were required only for due dates on or after July 29, 2026, with no PTET underpayment penalty in the first year. If your entity elected, the expected credit reduces what you owe, so factor it in before sizing your own January voucher.

No local income tax

Maine cities and towns levy property tax, not income tax, so the 1040ES-ME is the only state-level estimate. Massachusetts runs its own millionaire surtax and an 80% safe harbor, and anyone with income in both states needs both sets of vouchers. In conversations with freelancers while building Jupid, the state mistake I hear most is an April estimate nobody revisits; 2026, with Maine's mid-year worksheet revision, is the year that habit costs money.

The Fourth Voucher From Real Numbers: How Jupid Helps

Maine's January 31 exit only works if your books are finished in January, which for most freelancers means categorizing a year of transactions in a week. Jupid connects to your business bank account and sorts income and expenses with 95.9% accuracy as they happen, so the year-end profit you need for the 1040ES-ME worksheet is already there. Ask the AI accountant in WhatsApp or iMessage what you have earned in 2026 and how much is set aside, and you get the answer in the chat in real time. Try Jupid.

Sources

• 2026 Form 1040ES-ME, Estimated Tax for Individuals (revised July 2026): trigger, safe harbor, due dates, unusual event income, worksheet, mailing address
• 2025 Form 2210ME and instructions: penalty method, $1,000 floors, January 31 rule
• MRS 2026 Individual Income Tax Rates: brackets, surcharge, exemption, standard deduction
• MRS Interest Rates, 1992 to Present: 9% for 2026, 8% for 2027
• MRS 2026 Income/Estate Tax Updates: standard deduction for 2025–2027, surcharge, PTET
• Maine Tax Alert, August 2026: revised 1040ES-ME, PTET estimates, Rule 102
• MRS: Maine's New Pass-Through Entity Tax: 7.15% rate and 90% member credit
• 2025 Form 1040ME instructions: 36 M.R.S. § 5228(9), pension income deduction
• IRS Publication 505: federal estimated tax

This guide is for general educational purposes and does not constitute tax, legal, or accounting advice. It reflects the July 2026 Form 1040ES-ME, the 2025 Form 2210ME, and MRS guidance as reviewed 2026-10-29; Maine sets its interest rate each calendar year, and the 2026 Form 2210ME may refine the penalty table. For advice specific to your situation, consult a qualified tax professional or Maine Revenue Services at maine.gov/revenue.