---
title: "Advise on joining a person to a civil action"
url: "https://ailawframework.com/practice/commercial-litigation-and-dispute-resolution/advise-on-joining-a-person-to-a-proceeding/united-states"
type: "task_jurisdiction_version"
site: "AI Law Framework"
id: "A5-LA20261022-15-US"
practice_area: "Commercial Litigation & Dispute Resolution"
tier: "red"
lawyer_review: "required"
jurisdictions: ["US"]
last_reviewed: "2026-10-22"
---

# Advise on joining a person to a civil action

> From the instructions, record who would be joined, whether that person would join as a plaintiff or a defendant, and the facts given for the same transaction or occurrence, a common question, complete relief among the…

Canonical page: https://ailawframework.com/practice/commercial-litigation-and-dispute-resolution/advise-on-joining-a-person-to-a-proceeding/united-states  
Last reviewed: 2026-10-22

Site index for agents: https://ailawframework.com/llms.txt

## Key facts

| Fact | Value |
| --- | --- |
| Practice area | [Commercial Litigation & Dispute Resolution](https://ailawframework.com/practice/commercial-litigation-and-dispute-resolution.md) |
| Human involvement | Red: Lawyer writes; AI may check, clarify or collect data |
| How AI is used | From the instructions, record who would be joined, whether that person would join as a plaintiff or a defendant, and the facts given for the same transaction or occurrence, a common question, complete relief among the existing parties, and any interest that person claims. Do not decide that joinder is required and do not draft the motion. |
| What the lawyer must review | You decide whether Rule 20 or Rule 19 is met and you write the motion. Persons may join as plaintiffs, and persons may be joined as defendants, if the right to relief arises out of the same transaction, occurrence, or series, and any question of law or fact common to them will arise. A person whose joinder will not deprive the court of subject-matter jurisdiction, and who is subject to service of process, must be joined if, in that person's absence, the court cannot accord complete relief among existing parties, or if that person claims an interest and disposing of the action may as a practical matter impair that interest or leave a party at substantial risk of inconsistent obligations. If a required person has not been joined, the court must order that the person be made a party. A person who refuses to join as a plaintiff may be made a defendant or, in a proper case, an involuntary plaintiff. If joinder is not feasible, the court decides whether the action should proceed or be dismissed. Rule 19 is subject to Rule 23. Presenting the motion is a Rule 11 certification. Formal Opinion 512 requires review of generated text before filing. |
| Written for | United States |
| Applies to | [Advise on joining a person to a proceeding](https://ailawframework.com/practice/commercial-litigation-and-dispute-resolution/advise-on-joining-a-person-to-a-proceeding.md) |

## Checking plan

- What the AI does: From the instructions, record who would be joined, whether that person would join as a plaintiff or a defendant, and the facts given for the same transaction or occurrence, a common question, complete relief among the existing parties, and any interest that person claims. Do not decide that joinder is required and do not draft the motion.
- Basis: Checked against the linked sources on 22 October 2026. Confirm the current instrument before reliance.

## Notes

- Joinder that would defeat subject-matter jurisdiction, or of a person not subject to service, is not ordered under Rule 19(a).
- State joinder rules differ. This version is the federal rule.
- Rule 19(d) makes required joinder subject to Rule 23. A class is not joined person by person under Rule 19.

## Sources

- [Federal Rule of Civil Procedure 19, Required Joinder of Parties](https://www.law.cornell.edu/rules/frcp/rule_19) (checked 2026-10-22)
- [Federal Rule of Civil Procedure 20, Permissive Joinder of Parties](https://www.law.cornell.edu/rules/frcp/rule_20) (checked 2026-10-22)
- [Federal Rule of Civil Procedure 11, Signing Pleadings, Motions, and Other Papers; Representations to the Court; Sanctions](https://www.law.cornell.edu/rules/frcp/rule_11) (checked 2026-10-22)
- [ABA Formal Opinion 512, Generative Artificial Intelligence Tools (29 July 2024)](https://www.americanbar.org/content/dam/aba/administrative/professional_responsibility/ethics-opinions/aba-formal-opinion-512.pdf) (checked 2026-10-22)

*Practice guidance for planning and review. Confirm current primary sources and the requirements of the actual matter. This is general information, not legal advice.*