Rule 1-015.Amended and supplemental pleadings

Last amended December 31, 2017 · Last verified June 26, 2026

In one sentenceRule 1-015 governs amending and supplementing pleadings—amendment once as a matter of course, amendment by leave freely given, conforming pleadings to the evidence, and relation back of amendments.

Full Text of Rule 1-015

Text sizeJump to: (A) (B) (C) (D) (E)

A. Amendments. A party may amend its pleading once as a matter of course at any time before a responsive pleading is served or, if the pleading is one to which no responsive pleading is permitted and the action has not been placed on the trial calendar, the party may amend it at any time within twenty (20) days after it is served. Otherwise a party may amend its pleading only by leave of court or by written consent of the adverse party, and leave shall be freely given when justice requires. A party shall plead in response to an amended pleading within the time remaining for response to the original pleading or within ten (10) days after service of the amended pleading, whichever period may be the longer, unless the court otherwise orders.

B. Amendments to conform to the evidence. When issues not raised by the pleadings are tried by express or implied consent of the parties, they shall be treated in all respects as if they had been raised in the pleadings. Amendment of the pleadings as may be necessary to cause them to conform to the evidence and to raise these issues may be made on motion of any party at any time, even after judgment; but failure to amend does not affect the result of the trial of these issues. If evidence is objected to at the trial on the ground that it is not within the issues made by the pleadings, the court may allow the pleadings to be amended and shall do so freely when the presentation of the merits of the action will be subserved thereby and the objecting party fails to satisfy the court that the admission of the evidence would prejudice it in maintaining its action or defense on the merits. The court may grant a continuance to enable the objecting party to meet the evidence.

C. Relation back of amendments.

(1) Whenever the claim or defense asserted in the amended pleading arose out of the conduct, transaction, or occurrence set forth or attempted to be set forth in the original pleading, the amendment relates back to the date of the original pleading.

(2) When a party files a motion to amend a pleading prior to the running of the statute of limitations, changing the party against whom a claim is asserted, a ruling granting the motion relates back to the date the motion was filed if the motion was accompanied by a proposed amended pleading naming the new party.

(3) When a party files a motion to amend a pleading after the statute of limitations has run, changing the party against whom a claim is asserted, a ruling granting the motion relates back to the date of the original pleading if Paragraph (C)(1) of this rule is satisfied and, within the period provided by Rule 1-004(C)(2) NMRA for serving process, the party to be brought in by amendment

(a) has received such notice of the institution of the action that it will not be prejudiced in maintaining its defense on the merits; and

(b) knew or should have known that, but for a mistake concerning the identity of the proper party, the action would have been brought against it.

D. Supplemental pleadings. On motion of a party, the court may, on reasonable notice and on terms as are just, permit the party to serve a supplemental pleading setting forth transactions, occurrences, or events which have happened since the date of the pleading sought to be supplemented. Permission may be granted even though the original pleading is defective in its statement of a claim for relief or defense. If the court deems it advisable that the adverse party plead to the supplemental pleading, it shall so order, specifying the time therefor.

E. All matters set forth in one pleading. In every complaint, answer, or reply, amendatory or supplemental, the party shall set forth in one entire pleading all matters which, by the rules of pleading, may be set forth in the pleading, and which may be necessary to the proper determination of the action or defense.

End

Rule History

[As amended by Supreme Court Order No. 17-8300-020, effective for all cases pending or filed on or after December 31, 2017.]

Committee Commentary

2017 amendment

Introduction – Revisions to Rule 1-015(C) NMRA

Rule 1-015(C) NMRA is divided into three sections. Paragraph (C)(1) reiterates the first sentence of prior Paragraph C and remains unchanged. Paragraph (C)(2) addresses an issue raised in Snow v. Warren Power & Mach., Inc., 2015-NMSC-026, 354 P.3d 1285. Paragraph (C)(3) modifies prior Paragraph C by amending language in the rule to make it consistent with the Court’s holding in Galion v. Conmaco Int’l, Inc., 1983-NMSC-006, 99 N.M. 403, 658 P.2d 1130.

Both new Paragraphs (C)(2) and (C)(3) maintain the current language of prior Paragraph C making the rules applicable to an amendment “changing the party against whom a claim is asserted.” New Mexico has broadly construed this language. See Romero v. Ole Tires, Inc., 1984-NMCA-092, ¶ 14, 101 N.M. 759, 688 P.2d 1263 (“The word ‘changing’ should be given a liberal construction, so that amendments adding or dropping parties as well as amendments that substitute parties fall within the Rule.”); Romero v. Bachicha, 2001-NMCA-048, ¶ 12, 130 N.M. 610, 28 P.3d 1151 (“Rule 1-015(C) clearly encompasses the amendment of pleadings to correct misnomers.”).

New Paragraph (C)(2)

In Snow, 2015-NMSC-026, ¶ 33, the Court ruled that when a party filed a motion to add a new defendant shortly before the statute of limitations ran and the motion was granted after the statute of limitations ran, the motion was deemed to be granted on the date the motion was filed if the motion was accompanied by the proposed amended complaint. See Rule 1-007.1(C) NMRA (requiring the proposed pleading to be attached to the motion to amend the pleading). The Court did not impose a requirement that the person sought to be added as a defendant be notified of the proposal to amend the pleadings before the amended complaint is filed. Snow, 2015-NMSC-026, ¶¶ 35-36. The Court requested the Rules of Civil Procedure for the District Courts Committee consider whether to amend Rule 1-015 NMRA in light of its opinion. Id. ¶ 38.

The Court adopted the Committee’s recommendation for a new Paragraph (C)(2), which incorporates the Court’s holding in Snow by providing that motions to change a party granted in such factual situations may relate back to the date of the timely filing of the motion to change the party. The rule incorporates the Court’s requirement in Snow and Rule 1-007.1(C) NMRA that the proposed amended pleading must accompany the motion to amend, and the existing Paragraph C requirement that to relate back, amended pleadings must arise out of the conduct, transaction, or occurrence set forth or attempted to be set forth in the original pleading. See Paragraph (C)(1).

In Snow, the Court asked the Committee to consider whether a rule provision setting the specific time for serving the amended complaint on the new party should be adopted. The Court adopted the Committee’s recommendation that no specific time for accomplishing service should be set by rule. Instead, service must be “made with due diligence” as currently required in all cases by Rule 1-004(C)(2) NMRA. See Prieto v. Home Educ. Livelihood Program, 1980-NMCA-114, ¶ 12, 94 N.M. 738, 616 P.2d 1123 (providing that the court should exercise its inherent power and discretion to dismiss the complaint if the plaintiff does not exercise diligence in effectuating service). The possibility that plaintiff’s delay in serving the amended complaint may lead to dismissal provides adequate incentive for prompt service of the amended complaint upon the new defendant.

New Paragraph (C)(3)

Prior Paragraph C provided that the defendant to be brought in by amendment after the statute of limitations had run must have received listed notice “within the period provided for commencing the action against him.” Because “[a] party must . . . file the amended complaint within the period allowed under the statute of limitations,” Snow, 2015-NMSC-026, ¶ 18, the rule seemed to require that the new defendant receive the listed notice before the date that the statute of limitations ran.

In Galion, 1983-NMSC-006, ¶ 6, the Court noted that in all cases, service of process may be made on a defendant after the statute of limitations has expired if the complaint was filed before the statute of limitations ran and if plaintiff exercises due diligence when serving process thereafter. See Prieto, 1980-NMCA-114, ¶ 12. The Court ruled that an amendment changing the defendant similarly should relate back “as long as service of process was effected within the reasonable time allowed under the rules of civil procedure even though the limitations period had expired.” Galion, 1983-NMSC-006, ¶ 12.

Paragraph (C)(3) amends the language of former Paragraph C to conform to the holding in Galion. See also F.R.C.P. 15(c)(1)(C) (containing similar language). The amendment is not intended to modify the Galion Court’s ruling limiting Galion to cases involving a close relationship between the named defendant and the new defendant. See Galion, 1983-NMSC-006, ¶ 12.

[Adopted by Supreme Court Order No. 17-8300-020, effective for all cases pending or filed on or after December 31, 2017.]

Plain-English Summary

This rule controls how pleadings change over the life of a case. A party may amend once as a matter of course before a responsive pleading is served (or, where none is allowed and the case is not yet on the trial calendar, within twenty days). After that, amendment requires leave of court or the other side’s written consent, and leave is to be freely given when justice requires. When issues not in the pleadings are tried by consent, they are treated as if pleaded, and the court freely allows amendments to conform to the evidence unless the objecting party shows real prejudice.

The heart of the rule is relation back. An amendment relates back to the original pleading when it arises out of the same conduct, transaction, or occurrence. The rule also addresses changing the party sued: a motion filed before the limitations period runs relates back to the filing date if a proposed amended pleading was attached, and a motion filed after the period runs relates back if the new party received timely notice and knew the suit would have been brought against it but for a mistake about identity. As the committee commentary explains, these provisions were added in 2017 to track the Snow and Galion decisions. Supplemental pleadings, covering events since the original pleading, may be allowed by the court on just terms.

Frequently Asked Questions

When can I amend a pleading without permission?

Once as a matter of course before a responsive pleading is served, or—where no responsive pleading is allowed and the case is not yet on the trial calendar—within twenty days after serving it. Otherwise you need leave of court or written consent, and leave is freely given when justice requires.

What does “relation back” mean?

An amendment is treated as filed on the date of the original pleading when it arises out of the same conduct, transaction, or occurrence—important for the statute of limitations.

Can I amend to change the party I sued after the limitations period?

Yes, if the amendment arises from the same transaction and, within the time for serving process, the new party received notice that avoids prejudice and knew the suit would have been brought against it but for a mistake about identity.

Source & verification. Rule text and Committee commentary reproduced verbatim from the New Mexico Rules of Civil Procedure for the District Courts (Rule 1-015 NMRA), published by the New Mexico Compilation Commission (NMOneSource). Promulgated by the Supreme Court of New Mexico. The plain-English summary is original and draws on the official annotations. Last verified June 26, 2026. · Official source

Also known as: amended pleadingssupplemental pleadingsamend complaintrelation backleave to amend