Maine calendar and forms

Maine’s calendar runs on the federal dates. Form 1040ME is due April 15, 2027, the same day as the Form 1040; the four estimated payments fall on the federal dates; and the automatic six-month extension runs to October 15, 2027. Two Maine details are worth knowing on the way in. The extension is automatic and needs no form, but it is only good if at least 90% of the tax is paid by April 15; pay less and the late-payment penalty runs anyway. And since late 2025, the fourth estimated installment carries no penalty if the whole year’s tax is paid by January 31, which gives anyone with a December surprise two extra weeks.

The form side has one return, Form 1040ME, and a longer list of schedules than most states, because Maine starts from federal AGI and then applies its own additions, subtractions, deduction and credits. Most filers touch three or four pages: the return itself, Schedule 1S for the subtractions (Social Security and the pension deduction live there), Schedule A for credits, and Schedule PTFC/STFC for the property tax and sales tax fairness credits, which are the pages most often left off.

The 2027 filing season, dated

How the extension really works

Maine allows an automatic six-month extension of time to file. There is no form to request it. The condition is money: the Department’s rule is that at least 90% of the tax owed must be paid by the original due date to avoid the late-payment penalty, and interest runs on any unpaid balance from April 15 regardless. Someone who expects to owe sends the estimated balance by April 15 on the Maine Tax Portal, where no voucher is needed, or by mail with Form 1040EXT-ME, the extension payment voucher. The return then follows any time up to October 15. Miss October 15 and the failure-to-file penalty is the greater of $25 or 10% of the tax due; the late-payment penalty is 1% a month to a maximum of 25%. A longer extension, up to eight months in total, is possible only by written request before the six months run out.

Estimated payments

Maine requires estimated payments when the tax for the year, after withholding and credits, is expected to be $1,000 or more and the prior year’s tax was also $1,000 or more. The safe harbor is the smaller of 100% of last year’s tax, if last year was a full twelve months, or 90% of this year’s, paid in four equal, timely installments. There is no 110% tier for higher incomes. Farmers and fishermen may pay two-thirds of the current year instead, in one installment by January 15, or skip it by filing and paying by March 1. The penalty for a short or late installment is figured on Form 2210ME at the same rate as late-payment interest, compounded monthly. Payments go in on the Maine Tax Portal or with the Form 1040ES-ME voucher. The people caught out are the self-employed, landlords, and anyone with a large gain or a Roth conversion that had no Maine withholding.

The forms, in the order a filer meets them

Filing, paying and checking a refund

Most Maine returns are e-filed with the federal return through tax software or a preparer, and the Department processes an e-filed return far faster than paper. The state’s own route is the Maine Tax Portal at revenue.maine.gov, which the Department describes as free for Maine taxpayers for filing Form 1040ME, including Schedule PTFC/STFC, with some restrictions it lists on the Portal itself. The Portal does not file the federal return. It takes payments by bank debit, schedules them in advance, and handles payment plans. Direct deposit of a refund is available for refunds of $20,000 or less. The IRS Direct File program included Maine for the 2025 filing season; it was not offered for 2026, and the IRS has since ended the program.

Refund status is on the Portal, or by phone at (207) 624-9784, weekdays 9:00 a.m. to noon. Taxpayer assistance is (207) 626-8475, same hours; the Department does not prepare returns by phone. Forms by phone, 24 hours, (207) 624-7894. Collections and payment plans, (207) 621-4300, weekdays 8:00 to 5:00. Mail for correspondence goes to Maine Revenue Services, P.O. Box 1060, Augusta, ME 04332-1060; estimated and extension payments by check go to P.O. Box 9101, Augusta, ME 04332-9101, payable to Treasurer, State of Maine. If the IRS changes a federal return, the Department must be told within 180 days by filing Form 1040ME with the amended box checked and the federal change attached; interest runs from the original due date, but no penalty if the balance is paid with the amended return.