A plain-language guide to who files Form M-706, the nine-month timeline, and the financial information a family's CPA and attorney may ask an advisor to gather. It is educational and does not give legal or tax advice.
Estate Tax Guide · Last reviewed October 27, 2026
Short answer
A Massachusetts estate tax return, Form M-706, is required when a Massachusetts resident's gross estate plus adjusted taxable gifts exceeds $2,000,000 for deaths on or after January 1, 2023. The return and any tax are generally due nine months after death. The personal representative files it, usually with a CPA and attorney.
Last reviewed: October 27, 2026. Source: Massachusetts Department of Revenue, Estate Tax Guide (page updated April 23, 2026). Rules may change. Educational only; your CPA and attorney can address your situation.
According to the Massachusetts Department of Revenue (DOR), the personal representative of a decedent who was domiciled in Massachusetts must file a Massachusetts Estate Tax Return, Form M-706, when the gross value of the estate plus adjusted taxable gifts exceeds $2,000,000 for dates of death on or after January 1, 2023. For earlier dates of death, the threshold was $1,000,000 for deaths on or after January 1, 2006. The filing requirement for a nonresident who owned or transferred real estate or tangible personal property in Massachusetts is based on the total worldwide estate plus adjusted taxable gifts, and a Nonresident Decedent Affidavit (Form M-NRA) accompanies the return.
DOR also states that a personal representative may be held personally liable for any tax shown on the return that is not otherwise paid. For that reason, many families ask their attorney and CPA early who would act as personal representative and who would handle the filing.
The federal estate tax return is a separate filing with a separate threshold. The IRS states that the federal basic exclusion amount is $15,000,000 for calendar year 2026, and DOR states that later changes to federal estate tax law have no impact on the Massachusetts estate tax. An estate could need a Massachusetts return even when no federal return is required.
Sources: Massachusetts Department of Revenue, Estate Tax Guide (page updated April 23, 2026); IRS, What's new: Estate and gift tax. Verified against mass.gov and irs.gov as of October 27, 2026. Thresholds may change.
For how the threshold and the $99,600 credit work together, read how the Massachusetts estate tax exemption may apply to your household. For the difference between an estate tax and an inheritance tax, read how the Massachusetts estate tax differs from an inheritance tax.
Form M-706 is the return DOR uses to report the gross estate, the allowable deductions, and the Massachusetts estate tax, if any. DOR describes the tax as computed by reference to a federal credit for state death taxes under the Internal Revenue Code as of December 31, 2000, reduced by a $99,600 credit for deaths on or after January 1, 2023, and not below zero. DOR also states that the calculation steps changed for decedents dying on or after August 1, 2025, so the form and instructions depend on the date of death. Property is reported at its fair market value on the date of death, or on the alternate valuation date six months later.
The gross estate generally includes property in which the decedent had an interest, which DOR says may include jointly held property, annuities, certain lifetime transfers, and life insurance proceeds even when they are payable to someone other than the estate. DOR lists supporting documents that may need to accompany the return, such as a copy of the death certificate, the will and any trust, Letters of Authority, and an executed copy of a federal-format Form 706. The estate's CPA and attorney decide which documents apply and prepare them.
Sources: Massachusetts Department of Revenue, Estate Tax Guide (page updated April 23, 2026), Instructions for Form M-706 (dates of death on or after August 1, 2025) and Estate Tax Forms and Instructions (page updated January 9, 2026). Verified against mass.gov as of October 27, 2026.
Calculator call-out. To organize a general estimate before you meet with your professionals, try the Massachusetts estate tax calculator. It is an educational tool and does not give legal or tax advice, and its result is not a tax calculation or a filing determination for your estate.
Estimate your Massachusetts estate tax with the calculator →DOR states that if the gross estate exceeds the filing threshold for the year of death, the return and any tax payment are due nine months after the date of death. The table below summarizes the timeline DOR describes. Each step has conditions, and the estate's CPA and attorney confirm which apply.
| Milestone | What DOR describes | Source |
|---|---|---|
| Return and payment due | Nine months after the date of death | DOR, Tax due dates and extensions |
| Automatic extension of time to file | Six months, if at least 80% of the tax finally determined to be due is paid by the original due date; otherwise the extension is void | DOR, Estate Tax Guide |
| Extension of time to pay | Not automatic. Requested on Form M-4768 by the original due date, and granted only for undue hardship or reasonable cause; interest still accrues from the original due date | DOR, Form M-4768 |
| Late filing or late payment | Penalties of 1% per month, up to 25% of the tax, plus interest; the interest rate may change each quarter | DOR, Estate Tax Guide |
| Federal Form 706, if required | Generally nine months after death, with a six-month extension available if requested before the due date and the estimated tax is paid | IRS, Filing estate and gift tax returns |
Verified against mass.gov and irs.gov as of October 27, 2026. DOR's Estate Tax Guide was last updated April 23, 2026. Deadlines, extension terms, penalties and interest rates may change.
DOR notes that the return may be filed and the tax paid online through MassTaxConnect, and says that filing and paying electronically may speed the issuance of the closing letter. The IRS separately lists Form 706 and its instructions for federal filings.
DOR states that a lien arises automatically on real estate owned by a decedent at the time of death. When a return is required, a Certificate Releasing Massachusetts Estate Lien may be needed to sell or refinance real estate, and DOR says failing to file Form M-706 prevents its issuance. When the estate is below the filing threshold, DOR says an affidavit of the personal representative recorded at the registry of deeds is used instead. These are legal and tax steps handled by the family's attorney and CPA, and the timing may matter if a home sale is pending.
Source: Massachusetts Department of Revenue, Estate Tax Guide (page updated April 23, 2026), sections on releases of lien. Verified against mass.gov as of October 27, 2026.
An estate tax return depends on a complete and accurate picture of what the decedent owned and how it was held. A CPA and attorney may ask the household's financial advisor to pull together information the advisor already has access to. It is a gathering role only. The advisor does not decide what belongs on a return.
For the account-by-account follow-through on trusts, read the guide to funding a trust in Massachusetts. For how a QTIP election may appear on a Massachusetts return, read how a QTIP trust may interact with the Massachusetts estate tax threshold.
These items are educational starting points. Your professionals can tell you which are relevant to your situation.
Checklist for your attorney and CPA meetings
MSA Financial is a fee-based, fiduciary SEC-registered investment adviser. Michael Cammarata, CFP®, is not an attorney or CPA and does not draft legal documents, give legal or tax advice, or prepare tax returns. His role is to coordinate the financial side of the work with the professionals you choose. Read more about how a financial advisor coordinates estate planning with your attorney and CPA.
Your attorney drafts and finalizes legal documents and handles court and registry filings, such as the appointment of a personal representative.
Your CPA reviews estate and income tax effects, and prepares and files any Massachusetts or federal estate tax return.
The advisor organizes account values, titling, beneficiary and trust funding information, and tracks open items between your attorney and CPA.
Asset values, family circumstances and tax rules change, which may call for another review with your professionals.
According to the Massachusetts Department of Revenue, the personal representative of a decedent who was domiciled in Massachusetts must file Form M-706 when the gross estate plus adjusted taxable gifts exceeds $2,000,000 for dates of death on or after January 1, 2023. A nonresident who owned Massachusetts real estate or tangible personal property may also have a filing requirement. Whether a particular estate must file is a question for the family's attorney and CPA. Verified against mass.gov as of October 27, 2026.
The Department of Revenue states that the return and any payment are due nine months after the date of death. A six-month extension of time to file is automatic if at least 80% of the tax finally determined to be due is paid by the original due date. Interest may accrue on unpaid tax from the original due date, and an extension of time to pay is not automatic. Verified against mass.gov as of October 27, 2026.
No. They are separate returns with separate thresholds. The IRS states that the federal basic exclusion amount is $15,000,000 for calendar year 2026, while Massachusetts uses a $2,000,000 filing threshold. The Department of Revenue also asks for a copy of a federal-format Form 706 to accompany Form M-706, which the family's CPA or attorney prepares. Verified against mass.gov and irs.gov as of October 27, 2026.
A financial advisor who is not an attorney or CPA may gather and organize financial information, such as account values, titling, beneficiary designations and trust funding status, and may keep follow-up moving among the professionals the family chooses. The advisor does not prepare the return, give tax or legal advice, or draft legal documents.
It may. The filing test uses the gross estate, which may include real estate, retirement accounts, life insurance the person owned and business interests, plus adjusted taxable gifts. Values and ownership change over time, so a household near the threshold may want its CPA and attorney to review the numbers. An estate that does not need a return may still have a real estate lien question, which the attorney can address.
No. The Massachusetts estate tax is computed by the estate's CPA using the Department of Revenue's method, which includes a federal credit table and a $99,600 credit for deaths on or after January 1, 2023. The calculator on this site gives a general educational estimate only and is not a tax calculation for any estate.
This guide is for educational purposes only and does not constitute individualized legal, tax, or investment advice. It does not recommend any strategy for any reader. Investment advisory services are offered through MSA Financial, LLC, a Registered Investment Adviser (CRD #107768). MSA Financial is an SEC-registered investment adviser. Registration with the SEC does not imply a certain level of skill or training. Investing involves risk, including the potential loss of principal. Michael Cammarata is not an attorney or CPA and does not provide legal or tax advice. He does not draft legal documents or prepare tax returns. He coordinates with clients' existing estate attorneys and CPAs. Tax treatment depends on individual circumstances, and legal and tax advice should be obtained from your own attorney and CPA. The Massachusetts and federal figures and deadlines were verified against mass.gov and irs.gov as of October 27, 2026 and may change.