Check Massachusetts tax deadlines for individuals and C Corporations. Confirm due dates, extension rules, and exemptions for S Corps and Partnerships.
Massachusetts operates on a distinct filing calendar and imposes entity-level compliance beyond federal rules.
Massachusetts Tax Deadlines at a Glance (2026)
Entity Type | Return Due | Extension Deadline |
|---|---|---|
Individuals | April 15, 2026 | October 15, 2026 |
C Corporations | April 15, 2026 | October 15, 2026 |
S Corporations | March 16, 2026 | September 15, 2026 |
Partnerships | March 16, 2026 | September 15, 2026 |
Individuals
Applies to residents, part-year residents, and nonresidents with MA-source income.
Businesses
Massachusetts imposes an entity-level excise tax on corporations and some S corporations.
Fiscal-Year Entities
Due dates follow months after year-end, not calendar alignment.
Estimated Taxes
Required for individuals and corporations exceeding state thresholds.