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Rule 19.Joinder of Persons Needed for Just Adjudication

Part IV. Parties · Last verified September 4, 2026

In one sentenceRule 19 requires joinder of a person whose absence would prevent complete relief or impair their own interest, and sets four factors for deciding whether an action can proceed when that person cannot be joined.

Full Text of Rule 19

Text sizeJump to: (a) (b) (c) (d)

(a) Persons to be Joined if Feasible. A person who is subject to service of process shall be joined as a party in the action if (1) in his absence complete relief cannot be accorded among those already parties, or (2) he claims an interest relating to the subject of the action and is so situated that the disposition of the action in his absence may (i) as a practical matter impair or impede his ability to protect that interest or (ii) leave any of the persons already parties subject to a substantial risk of incurring double, multiple, or otherwise inconsistent obligations by reason of his claimed interest. If he has not been so joined, the court shall order that he be made a party. If he should join as a plaintiff but refuses to do so, he may be made a defendant. (Identical to Mass.R.Civ.P. 19(a))
(b) Determination by Court Whenever Joinder Not Feasible. If a person as described in subdivision (a)(1)-(2) hereof cannot be made a party, the court shall determine whether in equity and good conscience the action should proceed among the parties before it, or should be dismissed, the absent person being thus regarded as indispensable. The factors to be considered by the court include: first, to what extent a judgment rendered in the person's absence might be prejudicial to him or those already parties; second, the extent to which, by protective provisions in the judgment, by the shaping of relief, or other measures, the prejudice can be lessened or avoided; third, whether a judgment rendered in the person's absence will be adequate; fourth, whether the plaintiff will have an adequate remedy if the action is dismissed for nonjoinder. (Identical to Mass.R.Civ.P. 19(b))
(c) Pleading Reasons for Nonjoinder. A pleading asserting a claim for relief shall state the names, if known to the pleader, of any persons as described in subdivision (a)(1)-(2) hereof who are not joined, and the reasons why they are not joined. (Identical to Mass.R.Civ.P. 19(c))
(d) Deleted.
End

Plain-English Summary

Rule 19 is identical to its civil counterpart in (a) through (c). Subsection (d) is deleted.

Who must be joined

A person subject to service of process shall be joined if either test is met: in that person's absence complete relief cannot be accorded among those already parties; or the person claims an interest relating to the subject of the action and is so situated that disposing of the action without them may, as a practical matter, impair or impede their ability to protect that interest, or leave an existing party at substantial risk of double, multiple or inconsistent obligations.

If the person has not been joined, the court shall order that they be made a party. If they should join as a plaintiff but refuse, they may be made a defendant.

When joinder is not feasible

Subsection (b) is the equity-and-good-conscience test, and the rule supplies four factors in order: first, how far a judgment in the person's absence might prejudice them or those already parties; second, the extent to which protective provisions in the judgment, shaping of relief or other measures can lessen or avoid that prejudice; third, whether a judgment rendered in the absence will be adequate; fourth, whether the plaintiff will have an adequate remedy if the action is dismissed for nonjoinder.

The rule reserves the label rather than leading with it: the absent person is "thus regarded as indispensable" only if the court concludes the action should be dismissed.

Pleading around it

Subsection (c) requires a pleading asserting a claim for relief to state the names, if known, of any person described in (a)(1)-(2) who is not joined, and the reasons why. Note that Rule 20 — permissive joinder — is deleted from this set, so Rule 19 carries the joinder work on its own, with Rule 13(h) allowing additional parties to a counterclaim or cross-claim and Rule 24 covering intervention.

Frequently Asked Questions

When must a person be joined as a party?

Under Rule 19(a), when the person is subject to service of process and either complete relief cannot be accorded among the existing parties without them, or they claim an interest in the subject of the action and deciding it without them may impair their ability to protect that interest or leave an existing party at substantial risk of double, multiple or otherwise inconsistent obligations.

What happens if a necessary person cannot be joined?

Rule 19(b) requires the court to decide whether in equity and good conscience the action should proceed among the parties before it or should be dismissed, weighing four factors: prejudice, whether prejudice can be lessened by protective provisions or shaping of relief, whether a judgment in the person's absence will be adequate, and whether the plaintiff will have an adequate remedy if the action is dismissed for nonjoinder.

Do I have to say why someone was not joined?

Yes. Rule 19(c) requires a pleading asserting a claim for relief to state the names, if known to the pleader, of any persons described in subdivision (a)(1)-(2) who are not joined, and the reasons why they are not joined.

Is there permissive joinder of parties in this ruleset?

Rule 20 is deleted from the domestic relations rules. Rule 19 governs required joinder, Rule 13(h) allows persons other than the original parties to be made parties to a counterclaim or cross-claim, and Rule 24 covers intervention.

Source & verification. Rule text reproduced verbatim from the Massachusetts Rules of Domestic Relations Procedure as published by the Massachusetts Trial Court Law Libraries, current through amendments effective May 1, 2010. Promulgated by the Supreme Judicial Court of Massachusetts. Last verified September 4, 2026. · Official text
Also known as: joindernecessary partyindispensable partynonjoinderfailure to join