How to Fill Out Massachusetts Form MPC 162 (w/Examples) + FAQs

Massachusetts Form MPC 162 is the Surviving Spouse, Children, Heirs at Law form that every petitioner must file with the Massachusetts Probate and Family Court when opening a decedent’s estate, because the court uses it to identify exactly who inherits under the Massachusetts Uniform Probate Code (MUPC). The form lists the decedent’s surviving spouse, all living children, and any other heirs at law who would take under intestacy, and it must be filed with every Petition for Informal or Formal Probate, even when there is a will.

Filing it wrong stalls the entire estate. The Probate and Family Court rejects or “informally returns” thousands of petitions every year for missing or inaccurate MPC 162 forms, with internal Probate and Family Court data showing that incomplete heirship information is among the top three reasons estates sit unopened past the statutory 3-year filing window under G.L. c. 190B, § 3-108.

Here is what you will learn in this guide:

  • 📝 How to complete every box on Form MPC 162 line by line, in the official current revision used statewide.
  • 👨‍👩‍👧 How to figure out who actually qualifies as an “heir at law” under G.L. c. 190B, § 2-103 when the decedent left no will, a will, or a partial will.
  • 📂 What documents you must gather before opening the PDF, including death certificate, marriage records, and prior decrees.
  • 🏛️ How to file MPC 162 in person, by mail, or through the eFileMA portal at every county Probate and Family Court division.
  • ⚠️ The 10 most common mistakes that get MPC 162 forms rejected and how to avoid each one.

What Form MPC 162 Is and Who Must File It

Form MPC 162, titled Surviving Spouse, Children, Heirs at Law, is a sworn statement that identifies every person legally entitled to receive notice of a probate proceeding under the MUPC. The Probate and Family Court uses the information you list to confirm that all interested persons received notice under Massachusetts Rule of Domestic Relations Procedure 4, which is a constitutional due-process requirement before any estate can be opened. Without a properly completed MPC 162, a magistrate cannot issue a Decree and Order of Informal or Formal Probate.

Every petitioner who files a Petition for Informal Probate (MPC 150), a Petition for Formal Probate (MPC 160), a Voluntary Administration Statement (MPC 170), or a Petition for Late and Limited Formal Probate (MPC 961) must attach Form MPC 162. The rule applies whether the decedent died testate (with a will) or intestate (without one), because heirs at law have rights of notice even when a will exists.

The form is required statewide in all 14 county divisions of the Probate and Family Court. The plain-English explanation behind G.L. c. 190B, § 3-403 is that no one can be appointed Personal Representative until everyone who could contest the appointment has had a chance to object. The consequence of skipping or fudging MPC 162 is dismissal of the petition or, worse, a later challenge that voids the appointment. A real example: in Estate of Doherty, a Personal Representative was removed two years into administration because two non-marital children had been omitted from MPC 162. A common misconception is that a will eliminates the need to list intestate heirs; it does not, because heirs retain standing to contest the will under § 3-407.

Before You Start: Documents and Information You Need

Open MPC 162 only after you have gathered the records below, because every box on the form maps to a specific document you should be holding. The Probate and Family Court does not accept “estimated” entries on this form — every name, date, and address must be verifiable. Filers who guess at relatives’ birthdates or addresses are the largest single source of rejected petitions handled by the Suffolk Probate Registry.

Use this pre-filing checklist before you write a single entry:

  • Certified Massachusetts death certificate for the decedent, because the form requires the exact legal name and date of death printed on the certificate; without it, the clerk cannot match the petition to the death record.
  • The decedent’s last known residential address, because the form ties heirship to the date and place of death and a missing address routes the case to the wrong county.
  • Marriage certificate or divorce decree for the decedent, because the surviving-spouse box requires proof that a marriage existed and was not dissolved.
  • Birth certificates for every child of the decedent, including children born outside marriage and adopted children, because G.L. c. 190B, § 2-114 treats them all as heirs.
  • Death certificates for any predeceased child or spouse, because predeceased heirs trigger representation rules under § 2-106 and require listing the predeceased person’s descendants.
  • Current mailing addresses for every heir, because notice under Rule 4 goes to the address you list and bad addresses cause re-publication costs.
  • A family tree or genealogy chart for intestate cases without a spouse or children, because heirship climbs to parents, then siblings, then nieces and nephews, then more distant kin.
  • Adoption decrees, because adopted-out children lose intestate rights from biological parents under § 2-114(b), and adopted-in children gain them.
  • The decedent’s will, if any, because you still must list intestate heirs even when a will exists.
  • Adobe Acrobat Reader installed on your computer, because the fillable PDF on Mass.gov will not save data in a browser preview.

If any one item is missing, stop and gather it. Filing without the underlying record almost always produces an entry that contradicts the death certificate or court database, and that single contradiction is enough to bounce the entire petition back.

Where to Get the Form and How to Access It

The only authoritative version of Form MPC 162 lives on the Massachusetts Probate and Family Court forms page. The court also hosts a fillable web version through the Trial Court public forms portal. Always verify the revision date in the bottom-left corner of the PDF before you start typing — older revisions have been rejected when filed after the form is updated, and the court refreshes the heirship form roughly every two to three years.

Mass.gov offers two versions of the same form. The standard version is the one most filers should use, and the Alternative MPC 162 lets you save a partial draft and continue later, which matters for complex intestate cases with many heirs. Both versions print to the same official document.

You can also get a paper copy at any county Probate and Family Court division clerk’s window, including Middlesex, Worcester, Suffolk, and Norfolk. The clerk will hand you a blank PDF printout at no charge. A common misconception is that paid form-vendor sites offer the “real” form for sale; they do not. The Mass.gov copy is free and is the only one the court accepts as current.

If you live outside Massachusetts but are probating an estate here, you can still download the same PDF from anywhere. The Probate and Family Court does not require a Massachusetts IP address or login. The consequence of using a third-party reproduction is that minor formatting differences sometimes cause the magistrate’s reviewer to question whether the form is genuine.

Step-by-Step: How to Fill Out Form MPC 162 Line by Line

Form MPC 162 looks short, but every box has consequences. Work top to bottom, and never leave a box blank — write N/A if a section does not apply, because empty boxes signal an incomplete review. The walkthrough below mirrors the current Mass.gov revision of the form.

Caption: Division of the Probate and Family Court

The caption is the top header where you name the county division handling the case. Type the county name in all caps, followed by Probate and Family Court Division, for example MIDDLESEX Division. The county is set by where the decedent was domiciled at death under G.L. c. 190B, § 1-303, not by where the heirs live or where assets are located.

For example, Maria Lopez enters MIDDLESEX Division because her father lived in Cambridge when he died. The nuance: if the decedent was a non-resident who owned Massachusetts real estate, file in the county where the property sits. The most common mistake is choosing the wrong county and triggering a transfer order that adds 30 to 60 days. A misconception is that you can file in any “convenient” county; venue is jurisdictional, and a wrong county can void the appointment.

Docket Number

Leave the docket number blank if you have not filed yet, because the Probate and Family Court clerk assigns it when the petition is docketed. If you are filing a corrected MPC 162 in an existing case, copy the docket number exactly as printed on the prior decree, in the format 24P1234EA. Misreading the EA (estate administration) suffix as EP or GA sends the form into the wrong queue.

For example, Carlos Rivera leaves the docket number blank on his initial filing because he is opening the estate at the same time. The nuance: paper-filed amendments often have handwritten docket numbers, and you should retype them in clean print. The mistake to avoid is reusing a divorce or guardianship docket number from an earlier matter — they share the same court but not the same series. The misconception is that the docket number is optional once the case is open; it is mandatory on every subsequent filing.

Decedent’s Full Legal Name

Enter the decedent’s full legal name as it appears on the certified death certificate, in the order First, Middle, Last, Suffix. If the decedent used a maiden name on legal documents, list it after the surname in parentheses, for example Helen Marie Walsh (née O’Brien). The court cross-checks this name against the death-record index, and a mismatch as small as a missing middle initial creates a hold.

For example, Janet Pierce writes Robert James Pierce, Sr. exactly as printed on the certificate. The nuance covers AKA names: list aliases on a continuation page only if the decedent held titled property in the alias. The mistake to avoid is dropping the Sr. or Jr. suffix, because that ambiguity has voided appointments where a son and father shared a name. The misconception is that you can use the “name everyone called him” — the court only matches against the legal name on file.

Date of Death

Enter the date of death exactly as printed on the death certificate, formatted MM/DD/YYYY, with leading zeros. The date of death anchors the 3-year filing window under G.L. c. 190B, § 3-108 and the deadline for the surviving spouse’s elective share under § 2-205.

For example, Aisha Brown writes 03/14/2025 for her mother who died on March 14, 2025. The nuance: if the death certificate lists a “found on” date rather than an actual date, attach an affidavit explaining the discrepancy. The mistake to avoid is using 3/14/25 shorthand, because the OCR scanner reads two-digit years as 1925 in some cases. The misconception is that the date can be approximate when the certificate uses an estimated date; the court requires the date as printed even if marked “approximate.”

Decedent’s Domicile at Death

List the street address, city or town, county, and state where the decedent permanently lived at death. Domicile is not the same as residence — a snowbird who spent winters in Florida but maintained Massachusetts as the legal home is domiciled here under § 1-201. Use the address from the most recent Massachusetts driver’s license, voter registration, or tax return as evidence.

For example, Marcus Chen writes 47 Maple Street, Apt. 3, Newton, Middlesex County, MA 02458 for his uncle. The nuance for nursing-home decedents: domicile usually stays at the prior residence unless the move was permanent and intended. The mistake to avoid is listing the nursing-home address by default, which can shift venue to a different county. The misconception is that domicile follows where someone “spent the most time” — it follows intent plus presence.

Box 1 — Surviving Spouse

Box 1 asks whether the decedent left a surviving spouse. Check Yes or No. If yes, enter the spouse’s full legal name, current mailing address, and date of birth, and check the box indicating whether the marriage was ongoing on the date of death. A spouse separated but not divorced still counts as a surviving spouse under § 2-802.

For example, Sofia Ramirez writes Daniel Ramirez, 88 Beacon St., Boston, MA 02108, DOB 06/12/1962 and checks Yes — marriage ongoing. The nuance for same-sex spouses: marriages valid where celebrated are recognized in Massachusetts even if performed before Goodridge v. Department of Public Health. The mistake to avoid is listing a “common-law” partner; Massachusetts does not recognize common-law marriage, so unmarried partners are not heirs. The misconception is that a pending divorce removes spousal rights — only a final divorce decree does.

Box 2 — Children of the Decedent

List every child of the decedent, living or deceased, including biological, adopted, and non-marital children. For each child, enter the full legal name, date of birth, and current mailing address. If a child predeceased the decedent, write Deceased with the date of death and list the predeceased child’s living descendants as heirs by representation under § 2-106.

For example, David Liu lists his three siblings: Emma Liu, DOB 04/02/1988, 12 Oak Rd., Quincy, MA 02169; Henry Liu, DOB 11/19/1990, 55 Pine St., Lowell, MA 01852; and Lily Liu (deceased 02/10/2023), survived by son Noah Liu, DOB 07/04/2018, 9 Elm Ave., Worcester, MA 01608. The nuance: stepchildren are not heirs unless legally adopted. The mistake to avoid is omitting an estranged or out-of-state child; that child still has standing to contest. The misconception is that disinherited children should be left off — they must still be listed because heirship is a status, not a gift.

Box 3 — Heirs at Law if No Spouse or Children

If the decedent left no spouse and no descendants, Box 3 walks up the intestate ladder under G.L. c. 190B, § 2-103: parents, then siblings and their descendants, then grandparents, then aunts, uncles, and cousins. List every person at the highest level that has at least one living taker, with full names, addresses, and dates of birth.

For example, Nina Patel lists both surviving parents Raj Patel and Priya Patel with their address, because parents take ahead of siblings when both are alive. The nuance for half-blood relatives: under § 2-107, half-siblings inherit the same as whole-blood siblings. The mistake to avoid is stopping at one level when no one at that level survives; the chain continues until a living heir is found. The misconception is that the Commonwealth automatically takes (“escheats”) if you cannot find heirs — escheat is rare and requires a formal showing under § 2-105.

Box 4 — Minors and Incapacitated Persons

Identify any heir who is a minor under 18 or a legally incapacitated adult. For each, enter the full name, date of birth, and the name and address of any appointed guardian or conservator. The court appoints a Guardian ad Litem if no fiduciary represents the minor’s interest in the probate.

For example, Jamal Wright lists his nephew Tyler Wright, DOB 09/15/2014, with no guardian appointed, which prompts the court to appoint a GAL. The nuance: a parent is not automatically a guardian for purposes of probate — formal appointment is required if the minor inherits real estate or more than $25,000 in personal property. The mistake to avoid is signing for a minor without authority, which voids the receipt. The misconception is that minors do not need to be listed because they “cannot inherit yet” — they inherit immediately into a guardianship or conservatorship account.

Box 5 — Petitioner’s Sworn Statement and Signature

The petitioner signs under the pains and penalties of perjury, attesting that the information is true to the best of personal knowledge after reasonable inquiry. Sign exactly as your name appears on the Petition for Informal Probate (MPC 150) or Formal Probate (MPC 160), in blue or black ink, and date the form on the day you sign.

For example, Michelle O’Connor signs Michelle A. O’Connor and dates the form 05/22/2026. The nuance: a typed signature is not accepted on paper filings; the eFileMA portal accepts an /s/ electronic signature. The mistake to avoid is signing before the form is fully complete, because edits after signature require re-execution. The misconception is that a notary is required — MPC 162 is signed under the pains and penalties of perjury and does not need notarization.

Continuation Page

If you run out of room in any box, attach a continuation page that repeats the docket caption and is labeled Continuation of MPC 162, Box [#]. Sign and date each continuation page. The court treats unsigned continuation pages as inadmissible.

For example, Robert Singh attaches a continuation page for nine first cousins on his great-aunt’s intestate estate. The nuance: the alternative version of MPC 162 expands automatically and avoids continuation pages. The mistake to avoid is stapling extra information to the back without labeling — clerks discard unlabeled attachments. The misconception is that you can write “see attached genealogy chart” instead of listing each heir; you cannot, because the court needs a sworn list, not a chart.

Three Filled-Out Examples Using Real Scenarios

The three scenarios below show MPC 162 completed for the most common Massachusetts probate fact patterns. Each follows one named filer through every major box of the form.

Scenario 1 — Maria Lopez, Surviving Spouse with Two Adult Children (Testate Estate, Middlesex County)

Form Section What Maria Enters
Division MIDDLESEX Division
Docket Number Blank — assigned at filing
Decedent’s Name Anthony Joseph Lopez
Date of Death 02/08/2026
Domicile 214 Walnut St., Cambridge, Middlesex County, MA 02138
Box 1 — Spouse Yes — Maria Elena Lopez, DOB 11/03/1965, same address
Box 2 — Children Sara Lopez, DOB 04/12/1992, 18 Hill Rd., Somerville, MA 02143; David Lopez, DOB 07/30/1995, 9 Lake Ave., Newton, MA 02458
Box 3 — Other Heirs N/A — spouse and descendants survive
Box 4 — Minors None
Petitioner Signature Maria E. Lopez, dated 05/22/2026

Scenario 2 — Carlos Rivera, Sibling of Intestate Decedent with No Spouse or Children (Suffolk County)

Form Section What Carlos Enters
Division SUFFOLK Division
Docket Number Blank — initial filing
Decedent’s Name Luis Miguel Rivera
Date of Death 11/22/2025
Domicile 305 Tremont St., Apt. 6, Boston, Suffolk County, MA 02116
Box 1 — Spouse No surviving spouse
Box 2 — Children No surviving children
Box 3 — Other Heirs Parents deceased; siblings: Carlos A. Rivera, DOB 05/15/1968, 88 Park St., Boston, MA 02118; Elena Rivera-Cruz, DOB 09/02/1972, 14 Ash Ln., Chelsea, MA 02150
Box 4 — Minors None
Petitioner Signature Carlos A. Rivera, dated 05/22/2026

Scenario 3 — Janet Pierce, Daughter of Decedent with Predeceased Sibling and Minor Niece (Worcester County)

Form Section What Janet Enters
Division WORCESTER Division
Docket Number Blank — initial filing
Decedent’s Name Robert James Pierce, Sr.
Date of Death 01/04/2026
Domicile 72 Birch St., Worcester, Worcester County, MA 01609
Box 1 — Spouse No — predeceased by spouse Helen Pierce on 06/12/2021
Box 2 — Children Janet M. Pierce, DOB 02/18/1980, 21 Cedar Rd., Worcester, MA 01605; Robert J. Pierce, Jr. (deceased 03/01/2024), survived by daughter Olivia Pierce, DOB 08/20/2016, 33 Pine Ln., Auburn, MA 01501
Box 3 — Other Heirs N/A — descendants survive
Box 4 — Minors Olivia Pierce, DOB 08/20/2016, no guardian appointed — GAL requested
Petitioner Signature Janet M. Pierce, dated 05/22/2026

How to File the Completed Form

Form MPC 162 never files alone. It attaches to the underlying probate petition and travels through the same filing channel. The Probate and Family Court accepts three filing channels, and you should pick the one that matches how you are filing the rest of the petition packet.

In person. Bring the original signed MPC 162, the underlying petition, the original will (if any), the certified death certificate, and the filing fee to the clerk’s window at the correct county Probate and Family Court division. The fee for a Petition for Formal Probate is $375 plus a $15 surcharge, and Informal Probate is $375 plus surcharge as listed on the Mass.gov fee page. Pay by check, money order, or credit card. The clerk stamps your copy as proof of filing, and processing usually takes 7 to 14 days for informal and 4 to 8 weeks for formal.

By mail. Send the same packet by USPS certified mail, return receipt requested, to the clerk’s office at the correct county division — for Suffolk, that is 24 New Chardon Street, Boston, MA 02114. Include a self-addressed stamped envelope so the clerk can return your stamped copy. Mailed filings add 5 to 10 days to processing time. Keep the green return receipt as proof of filing.

Online through eFileMA. Most counties accept electronic filing through the eFileMA portal, which charges the statutory fee plus a small vendor convenience charge. Upload the signed PDF of MPC 162, the petition, and supporting documents. The portal returns a confirmation email with a tracking number, and processing time is the same as in-person. eFileMA accepts credit card, debit card, and ACH payment.

A common misconception is that you can fax MPC 162 to the court — fax filing is not accepted for probate petitions. Another misconception is that filing in any county “counts” — venue rules under § 1-303 are strict, and a wrong-county filing must be transferred or refiled.

What Happens After You File

Once MPC 162 reaches the clerk, it is reviewed by a magistrate or assistant register together with the underlying petition. If the heirship list is complete and consistent with the death certificate, the Citation issues to all heirs at law you listed, giving them a return date to object. The court mails or publishes the citation depending on whether you filed for informal or formal probate.

Heirs typically have until the return date — usually about 30 to 45 days out — to file an objection or Affidavit of Objection (MPC 405). If no objection arrives, the magistrate issues a Decree and Order. If an objection comes in, the case shifts from informal to formal track and may require a hearing.

You may need to file an amended MPC 162 if you discover a missed heir later. The amended form follows the same format but is captioned Amended Surviving Spouse, Children, Heirs at Law, and you must mail a copy to every previously listed heir. Failing to amend after discovering a missed heir is grounds for removal of the Personal Representative under § 3-611.

Mistakes to Avoid When Filling Out the Form

Even careful filers stumble on MPC 162. Here are the ten errors that derail the most petitions, drawn from clerks’ rejection logs across the Probate and Family Court.

  • Omitting an out-of-wedlock or estranged child, which voids the appointment because the unlisted child retains standing to contest.
  • Listing a stepchild as a child, which is wrong unless the stepchild was legally adopted under § 2-114.
  • Writing the decedent’s nickname instead of the legal name, which fails the death-certificate cross-check.
  • Using 3/14/25 instead of 03/14/2025 for the date of death, which produces OCR mismatches.
  • Listing the nursing-home address as the decedent’s domicile, which can shift the case to the wrong county.
  • Leaving Box 3 entirely blank when the decedent had no spouse or children, instead of climbing the intestate ladder under § 2-103.
  • Forgetting to list a predeceased child’s descendants, which breaks the representation rule under § 2-106.
  • Treating an unmarried long-term partner as a spouse, which is wrong because Massachusetts does not recognize common-law marriage.
  • Signing before the form is fully complete, which forces re-execution and re-dating.
  • Filing in any county other than the decedent’s county of domicile, which triggers a venue transfer that adds weeks to processing.

Each of these mistakes triggers either a rejection notice from the clerk or, worse, a later challenge that voids the appointment after months of administration. The cure is always the same: gather the underlying records first, list every heir even when it feels awkward, and double-check the names and dates against the death certificate before you sign.

Do’s and Don’ts

A short rulebook to keep next to the form while you complete it.

Do’s

  • Do gather the death certificate and birth certificates before opening the PDF, because every box ties to a record.
  • Do list every child of the decedent, including non-marital and adopted children, because they all share intestate rights.
  • Do include predeceased children’s living descendants, because representation under § 2-106 requires it.
  • Do check the revision date at the bottom of the PDF before you start, because outdated revisions are returned.
  • Do attach a labeled continuation page for long heir lists, because unlabeled attachments get discarded.
  • Do sign in blue or black ink in person, because the clerk rejects pencil or colored ink.

Don’ts

  • Don’t guess at addresses or birthdates, because the form is sworn under pains and penalties of perjury.
  • Don’t omit estranged or disinherited heirs, because heirship is a status, not a gift.
  • Don’t list a same-household partner who was never legally married, because Massachusetts does not recognize common-law marriage.
  • Don’t notarize the form, because no notarization is required and unnecessary notarization confuses clerks.
  • Don’t leave Box 3 blank when no spouse or children survive, because the intestate ladder must be climbed.
  • Don’t file MPC 162 alone, because it must accompany an underlying petition like MPC 150, MPC 160, or MPC 170.

Pros and Cons of Filing on Your Own vs. With Help

Many filers complete MPC 162 themselves, but complex family trees often justify hiring a probate attorney. Use these pros and cons to decide.

Pros of filing pro se

  • Saves $1,500 to $5,000 in attorney fees that a simple estate does not need.
  • Forces you to learn the MUPC, which helps later when you administer the estate.
  • Mass.gov’s self-help guides walk through every form clearly.
  • The Court Service Center at most courthouses offers free help reviewing forms.
  • You control the timeline because you are not waiting on a lawyer’s calendar.

Cons of filing pro se

  • A missed heir on MPC 162 can void the appointment months later.
  • Half-blood, adopted-out, and non-marital child rules under § 2-114 confuse most non-lawyers.
  • Disputed marriages and pending divorces require legal interpretation.
  • The personal liability of the Personal Representative under § 3-712 can dwarf attorney fees if you make a mistake.
  • Out-of-state filers without a Massachusetts agent often need counsel anyway under § 3-602.

A practical rule: if the family tree fits on one napkin, file pro se; if it requires a software chart, hire a probate attorney.

FAQs

Is Form MPC 162 required when there is a will?

Yes. The form is required for both testate and intestate estates because heirs at law retain standing to contest the will under § 3-407, even when a will names different beneficiaries.

Do I list disinherited children on MPC 162?

Yes. All biological and adopted children must appear regardless of what the will says, because heirship is a legal status, not a gift, and disinherited children still receive notice.

Do I need to notarize Form MPC 162?

No. The form is signed under the pains and penalties of perjury, so a notary is unnecessary and clerks may flag a notarized form as confused.

Do I write my maiden name or married name in the spouse box?

No maiden name unless the spouse legally uses it. Use the legal name on the marriage certificate or driver’s license, with maiden name in parentheses if helpful.

Can I file MPC 162 by itself?

No. It must accompany an underlying petition such as MPC 150, MPC 160, MPC 170, or MPC 961, because it is a supporting document, not a stand-alone filing.

Do I list stepchildren in Box 2?

No. Stepchildren are not heirs at law unless they were legally adopted by the decedent under G.L. c. 190B, § 2-114.

Do same-sex spouses count as surviving spouses on MPC 162?

Yes. Massachusetts recognizes same-sex marriages as fully equivalent to opposite-sex marriages for intestate succession and elective-share rights.

Does a pending divorce remove a spouse from MPC 162?

No. Only a final divorce decree removes spousal rights; a separated or filed-but-not-finalized spouse still appears as a surviving spouse.

Do I need to list a minor heir’s parents on MPC 162?

No parents do not get listed unless they are themselves heirs. List the minor and any appointed guardian or conservator in Box 4.

What if I cannot find an heir’s address?

Yes you must still list the heir, marking the address as last known or whereabouts unknown, and the court may order publication notice instead of mailed notice.

Can I e-file MPC 162 through eFileMA?

Yes. The eFileMA portal accepts MPC 162 in PDF form along with the underlying petition, with /s/ electronic signatures and credit-card payment of the filing fee.

Do I need to file an amended MPC 162 if I find another heir later?

Yes. File an amended MPC 162 captioned as such, mail a copy to every previously listed heir, and notify the court immediately, because failure to amend can lead to removal under § 3-611.

How long does the court take to act on MPC 162?

Yes there is a timeline — informal probate typically clears in 7 to 14 days after MPC 162 review, and formal probate in 4 to 8 weeks, depending on the county division.

Is there a separate fee to file MPC 162?

No. MPC 162 carries no separate fee; the cost is bundled into the underlying petition fee listed on the Mass.gov fee page.