Detailed Answer

Short answer: Yes. If a co-owner (for example, your deceased sibling) had an ownership interest in land, that interest does not disappear at death — it passes to the decedent’s estate or heirs (by will or under New Jersey intestacy rules). A partition action that seeks to divide or sell the property should include everyone who holds a legal or equitable interest in the property, including heirs of a deceased co-owner. To add them you must identify the heirs, name them as parties in the partition complaint, and serve them properly (or, when heirs are unknown, ask the court for substitute service or appointment of a guardian ad litem or estate representative).

How this works under New Jersey law (basic legal framework)

Partition is an equitable action to divide real property among co-owners or to order sale and division of proceeds. In New Jersey, a partition plaintiff must make all persons who have an interest in the property parties to the lawsuit so the court can fully determine title and rights and finally divide the property. That includes:

living co-owners named on the deed;
the decedent’s personal representative (if an estate has been opened); and
the decedent’s heirs or beneficiaries who have succeeded to the decedent’s interest (if no personal representative is involved, the heirs may be the proper parties).

Practical implications: if your sibling died owning an interest, you must trace whether the estate has a filed will or an opened probate. If a personal representative (executor/administrator) has been appointed, that representative should be joined to the partition action on behalf of the estate. If no estate was opened, you will usually join the known heirs directly as parties.

Steps to add heirs to a partition action

Do a title and probate check. Get a current title report and check county probate records (surrogate’s/estate records) to see whether a will or estate administration exists. County clerk or surrogate office records will show if a personal representative was appointed.
Identify the rightful heirs. If there is a will, the named devisees/beneficiaries are the people to join. If no will, New Jersey intestacy rules determine heirs (spouse, children, parents, siblings, etc.). If the decedent’s share passed to their heirs, those heirs are necessary parties.
Name the correct parties in the complaint. Prepare your partition complaint to list each current owner and each heir (or the estate’s personal representative) as a defendant/party. Include addresses and, if possible, the interest each person claims.
Serve each party properly. Serve process on each named defendant according to New Jersey rules (personal service, substituted service, or certified mail where allowed). If a personal representative exists, serve on that representative at the estate address.
Unknown or unlocatable heirs: If you cannot find an heir, ask the court for permission to (a) serve by publication, (b) appoint a guardian ad litem to represent unknown or minor interests, or (c) appoint a special administrator or conservator. Courts allow substituted or constructive service where necessary to bind unknown parties once the court is satisfied you made reasonable efforts to locate them.
Minors or incapacitated persons: The court normally requires appointment of a guardian ad litem (or conservator/guardian) to represent those parties’ interests before final distribution.
Provide proof to the court: Include affidavits of diligent search, copies of probate filings (if applicable), and proof of service or publication so the judge can determine whether parties were properly notified.

What if the estate was opened (executor/administrator)?

If a personal representative has been appointed, courts typically prefer joining the representative rather than each heir individually because the representative represents the estate’s interest. Serve the personal representative; they can appear, protect the estate’s interest, and distribute any proceeds after the court’s order is final. If the estate is open and the personal representative is adverse or refuses to act, heirs may still be added if appropriate.

Court tools and remedies

The court can determine who owns what share, order a physical division if practicable, or order a sale and allocate proceeds according to ownership interests.
When heirs are unknown, the court can permit notice by publication and can appoint a guardian ad litem to protect absent or minor parties.
If necessary, the court may order the sale with proceeds held pending later claims if additional heirs surface after the sale.

Where to read official New Jersey resources

New Jersey courts maintain self-help and practice resources about estates, service, and civil process: see the New Jersey Courts self-help and rules pages at https://www.njcourts.gov/. For general legislative materials and statutes, see the New Jersey Legislature site at https://www.njleg.state.nj.us/. These pages will point you to local county surrogate (probate) offices and court procedure information.

Practical example (hypothetical)

Hypothetical facts: You and your sibling own a house as tenants in common. Your sibling dies intestate (no will) and leaves two children. No estate has been opened. To partition the property you would:

Obtain a title report showing your sibling’s interest;
identify and name the two children (the heirs) as defendants in the partition complaint, listing their relationship to the decedent and addresses;
serve them with process; if an heir is a minor, ask the court to appoint a guardian ad litem to protect that minor’s share;
ask the court to determine ownership shares and to order partition in kind or sale and division of proceeds among you and the heirs.

When you should get help from a lawyer

Consider getting an attorney if:

heirs are unknown, numerous, or uncooperative;
there are minors, incapacitated heirs, or guardianship issues;
title issues, mortgages, liens, or tax complications exist;
you anticipate a contested valuation or complex property division.

Key takeaways

Heirs of a deceased co-owner generally must be included in a partition action if they hold or may claim the decedent’s interest.
Identify whether a personal representative of the estate exists; if so, join that representative. If not, name the heirs themselves.
If heirs are unknown or unlocatable, ask the court for substitute service or appointment of a guardian ad litem.
Proper party joinder and service are essential — without them the court cannot finally resolve ownership and order distribution.

Helpful Hints

Run a full title search early to identify all recorded owners and liens.
Check the county surrogate’s office for probate filings before naming parties.
Keep careful records of your efforts to locate heirs — the court will want proof of diligent search before allowing service by publication.
If an heir is a minor or legally incapacitated, expect the court to require a guardian ad litem or court-appointed representative.
Consider a short, targeted consultation with a New Jersey real property attorney to draft the complaint, because correct party joinder and service are crucial to finalizing your partition case.
If you expect dispute over valuation, consider requesting an appraisal or asking the court to appoint a referee or commissioner to handle accounting/valuation issues.

Disclaimer: This article is for general informational purposes and does not constitute legal advice. I am not a lawyer. For advice about your specific situation, consult a licensed New Jersey attorney who can assess facts, review title and probate records, and guide you through filing or defending a partition action.