State
Massachusetts (MA)
Original Deadline
April 15, 2026
Extended Deadline
October 15, 2026
Extension Type
✓ Automatic if 80% Paid
State Agency
Massachusetts DOR

Massachusetts state flagMA — Massachusetts

Massachusetts Personal Income Tax Extension — What You Need to Do

Massachusetts grants a 6-month extension to October 15, 2026, but it’s conditioned on payment, not just a form. If you owe $0 additional tax, you’re automatically extended with no form needed. If you owe tax, you must file Form M-4868 and have paid at least 80% of your total tax liability by April 15, 2026 for the extension to be valid — Massachusetts’s threshold is stricter than the 90% rule used by several other states.

Automatic — with a payment condition. Owe $0 additional Massachusetts tax? Your extension to October 15, 2026 is automatic, no form needed. Owe tax? File Form M-4868 and pay at least 80% of your total liability by April 15, 2026 to keep the extension valid.

Extended to October 15, 2026
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Massachusetts Extension Checklist — 2026

Two things to handle. Whether you need Form M-4868 depends on whether you owe tax.

1
Due by
April 15, 2026

Pay At Least 80% of Your Massachusetts Tax (File Form M-4868 If So)

Massachusetts’s 80% rule is stricter than most states. Pay less than 80% and the extension itself becomes invalid — not just penalty-triggering — meaning you’re treated as if you never requested an extension at all. File Form M-4868 whenever you owe tax.
No fee
Bank Account via MassTaxConnect
MassTaxConnect
File Form M-4868 and pay in the same session.
Mail
Check with Form M-4868

Mass. DOR
PO Box 419540
Boston, MA 02241-9540

Payments of $5,000+ must be made electronically, or a $100 penalty applies.

2
Due by
October 15, 2026

File Federal + Massachusetts Return

File your federal return now and add your Massachusetts state return — Form 1 — in the same session. Filing sooner means a faster refund. Your Massachusetts extended deadline is October 15.

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Massachusetts Late Filing & Payment Penalties — What It Costs to Wait

Falling short of the 80% threshold doesn’t just add a penalty — it can void your extension entirely, making your return late from April 15, not October 15.

Charge Type Rate Cap Trigger
Late Filing Penalty 1% of tax due per month (or fraction) 25% Return filed late without a valid extension (extension is void if the 80% rule isn’t met)
Late Payment Penalty 1% of tax due per month (or fraction) 25% Tax unpaid after April 15, 2026
Interest 8% per year (Q3 2026; adjusted quarterly) No cap Accrues from April 15 on any unpaid balance

Example: If you owe $5,000 and pay only $3,000 (60%) by April 15 without filing Form M-4868, your extension is invalid — your return is treated as late starting April 15, not October 15. Filing in September (about 5 months late) would trigger the full 25% late-filing penalty cap ($1,250), plus the late-payment penalty and 8% interest. Paying at least $4,000 (80%) and filing Form M-4868 keeps the extension valid, even though the remaining $1,000 still accrues interest and a late-payment penalty until it’s paid.

Massachusetts State Extension Details

Extension Type Automatic — Conditioned on 80% Payment or $0 Tax Due
Original Filing Deadline April 15, 2026
Extended Filing Deadline October 15, 2026
Extension Period 6 months
Extension Form Form M-4868 — required unless $0 additional tax is due
Return Form Form 1 (resident) / Form 1-NR/PY (nonresident & part-year resident)
Federal Extension Required? No — Massachusetts’s extension is independent of federal extension status
Payment Deadline April 15, 2026 (extension does not extend time to pay)
The 80% Rule Pay at least 80% of total tax liability by April 15, 2026 (withholding, estimates, and credits count) — falling short voids the extension itself, not just triggers a penalty
Online Payment Portal MassTaxConnect
Return Mailing Address (refund) Mass. DOR, PO Box 7000, Boston, MA 02204
Return Mailing Address (payment enclosed) Mass. DOR, PO Box 7003, Boston, MA 02204
Extension Payment Mailing Address Mass. DOR, PO Box 419540, Boston, MA 02241-9540
State Agency Massachusetts Department of Revenue
Late Filing / Late Payment Penalty 1% per month each, up to 25% each
Interest Rate 8% per year (Q3 2026, federal short-term rate + 4 points, adjusted quarterly)

Massachusetts Tax Extension — Frequently Asked Questions

Do I need to file Form M-4868?

Only if you owe additional Massachusetts tax. If your return shows $0 due, the extension is automatic with no form required.

What happens if I don’t pay 80% by April 15?

Your extension becomes invalid — you’re treated as if you never requested one. That means your return is late from April 15 forward, exposing you to the full late-filing penalty in addition to late-payment penalties and interest.

Does a federal extension cover Massachusetts?

No. Massachusetts’s extension is entirely independent of federal extension status — it’s governed solely by Form M-4868 and the 80% payment rule.

What if I’m due a refund?

If you’re due a refund, there’s no tax owed, so your extension is automatic with no form needed. You’ll still want to file as soon as possible to get your refund.

Is the interest rate fixed all year?

No. Massachusetts recalculates its interest rate quarterly, based on the federal short-term rate plus four percentage points, compounded daily.

Which Massachusetts return form do I need?

Form 1 is for full-year residents. Nonresidents and part-year residents file Form 1-NR/PY.

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