Ariz. R. Civ. P. 15

As amended through December 8, 2021
Rule 15 - Amended and Supplemental Pleadings
(a) Amendments Before Trial.
(1)Amending as a Matter of Course. A party may amend its pleading once as a matter of course:
(A) no later than 21 days after serving it if the pleading is one to which no responsive pleading is permitted; or
(B) no later than 21 days after a responsive pleading is served if the pleading is one to which a responsive pleading is required or, if a motion under Rule 12(b), (e), or (f) is served, on or before the date on which a response to the motion is due, whichever is earlier.
(2)Other Amendments. In all other instances, a party may amend its pleading only with leave of court or with the written consent of all opposing parties who have appeared in the action. Leave to amend must be freely given when justice requires.
(3)Effect on Pending Motions. After the filing of a motion under Rule 12(b), (e), or (f), amending a pleading as a matter of course does not, by itself, make moot the motion as to the adequacy of the pleading's allegations as revised in the amended pleading and does not relieve a party opposing the motion from filing a timely response.
(4)Proposed Pleading as an Exhibit. A party moving for leave to amend a pleading must attach a copy of the proposed amended pleading as an exhibit to the motion. The exhibit must show the respects in which the proposed pleading differs from the existing pleading by bracketing or striking through the text to be deleted and underlining the text to be added.
(5)Filing and Response. If a motion for leave to amend is granted, the moving party must file and serve the amended pleading within 10 days after the entry of the order granting the motion, unless the court orders otherwise. If the pleading is one to which a responsive pleading is required, an opposing party must answer or otherwise respond to an amended pleading within the time remaining for response to the original pleading or within 10 days after the amended pleading is served, whichever is later, unless the court orders otherwise.
(b) Amendments During and After Trial.
(1)Based on an Objection at Trial. If, at trial, a party objects that evidence is not within the issues raised in the pleadings, the court may permit the pleadings to be amended. The court should freely permit an amendment when doing so will aid in presenting the merits and the objecting party fails to satisfy the court that the evidence would unfairly prejudice that party's claim or defense on the merits. The court may grant a continuance to enable the objecting party to respond to the evidence.
(2)For Issues Tried by Consent. When an issue not raised by the pleadings is tried by the parties' express or implied consent, it must be treated in all respects as if it had been raised in the pleadings. A party may move-at any time, even after judgment-to amend the pleadings to conform to the evidence and to raise an unpleaded issue. But failure to amend does not affect the result of the trial of that issue.
(c) Relation Back of Amendments.
(1)Amendment Adding Claim or Defense. An amendment relates back to the date of the original pleading if the amendment asserts a claim or defense that arose out of the conduct, transaction, or occurrence set forth, or attempted to be set forth, in the original pleading.
(2)Amendment Changing Party. An amendment changing the party against whom a claim is asserted relates back if:
(A) Rule 15(c)(1) is satisfied; and
(B) within the applicable limitations period-plus the period provided in Rule 4(i) for the service of the summons and complaint-the party to be brought in by amendment:
(i) has received such notice of the institution of the action that it will not be prejudiced in maintaining a defense on the merits; and
(ii) knew or should have known that, but for a mistake concerning the identity of the proper party, the action would have been brought against the party.
(3)Service. Service of process in compliance with Rule 4.1(h), (i), or (j) satisfies Rule 15(c)(2)(B)(i) and (ii) with respect to the state, county, or municipal corporation- or any agency or officer of those entities-to be brought into the action as a defendant.
(d) Supplemental Pleadings. On motion and reasonable notice, the court may permit a party to file a supplemental pleading setting forth any transaction, occurrence, or event that happened after the date of the pleading to be supplemented. A court may permit supplementation even though the original pleading is defective in stating a claim for relief or defense. The court may order the opposing party to answer or otherwise respond to the supplemental pleading within a specified time.

Ariz. R. Civ. P. 15

Amended effective January 1, 2017.

Supplemental State Bar Committee Note

Amendment to Rule 15(c)

In Ritchie v. Grand Canyon Scenic Rides, 165 Ariz. 460, 799 P.2d 801 (1990), the Arizona Supreme Court held that the "period provided by law for commencing the action" referred to in the second sentence of Rule 15(c) includes the time allowed for service of process. Accordingly, when a party files a claim prior to the expiration of the statute of limitations, an amendment to the pleadings that adds a party, or changes the party, against whom the claim is asserted will relate back under Rule 15(c), if the new party is served within the time prescribed by the applicable statute of limitations plus the time allowed for service of process under Rule 4(i), and if the claim asserted in the amended pleading arose out of the same occurrence set forth in the original pleading.

State Bar Committee Note

1966 Amendment to Rule 15(c)

The amendment to this rule provides for relation back of pleading amendments in cases in which a complainant makes a mistake in designating against whom his claim is asserted. The amendment applies primarily but not exclusively to public officials, as where a party may mistakenly suppose that a particular person occupies an office when in fact by change of circumstances it is occupied by someone else; and it also covers cases in which a suit names an agency when it should name an individual. For example, a plaintiff might sue the "State Treasury Department" instead of the "State Treasurer." While this problem has not been substantial in Arizona, it has been substantial in the federal system, and the amendment is therefore adopted in the interest of conformity.