(a) Amendments. A party may amend a pleading as a matter of course at any time before a responsive pleading is served, or, if a pleading is one to which no responsive pleading is permitted and the action has not been placed upon the trial calendar, the party may so amend it at any time within thirty days after it is served. On sustaining a motion to dismiss for failure to state a claim upon which relief can be granted, pursuant to Rule 12(b)(6), or for judgment on the pleadings, pursuant to Rule 12(c), leave to amend shall be granted when justice so requires upon conditions and within time as determined by the court, provided matters outside the pleadings are not presented at the hearing on the motion. Otherwise a party may amend a pleading only by leave of court or upon written consent of the adverse party; leave shall be freely given when justice so requires. A party shall plead in response to an amended pleading within the time remaining for response to the original pleading or within ten days after service of the amended pleading, whichever period may be longer, unless the court otherwise orders.
Rule 15.Amended and Supplemental Pleadings
Chapter III: Pleadings and Motions · Last amended July 1, 2020 · Last verified July 14, 2026
In one sentenceRule 15 lets a party amend a pleading freely before a response is filed, requires the court's leave or the opposing party's consent afterward — freely given when justice requires, with no cap on how many times a Mississippi pleader may amend as of course — and sets the relation-back rules that let a later amendment take on the filing date of the original pleading, including one that corrects a party's identity.
Full Text of Rule 15
(b) Amendment to Conform to the Evidence. When issues not raised by the pleadings are tried by expressed or implied consent of the parties, they shall be treated in all respects as if they had been raised in the pleadings. Such amendment of the pleadings as may be necessary to cause them to conform to the evidence and to raise these issues may be made upon motion of any party at any time, even after judgment; but failure so 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 such evidence would prejudice the maintaining of the action or defense upon the merits. The court may grant a continuance to enable the objecting party to meet such evidence. The court is to be liberal in granting permission to amend when justice so requires.
(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) An amendment changing the party against whom a claim is asserted relates back if the foregoing provision is satisfied and, within the period provided by Rule 4(h) for service of the summons and complaint, the party to be brought in by amendment:
(a) has received such notice of the institution of the action that the party will not be prejudiced in maintaining the party’s 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 the party.
(3) An amendment pursuant to Rule 9(h) is not an amendment changing the party against whom a claim is asserted and such amendment relates back to the date of the original pleading.
(d) Supplemental Pleadings. Upon motion of a party the court may, upon reasonable notice and upon such 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.
Advisory Committee Notes
Mississippi Rule 15(a) varies from Federal Rule 15(a) in that the federal rule permits a party to amend the pleading only once as a matter of course. The Mississippi rule places no limit on the number of such amendments.
If a party files an amended pleading without leave of court when leave of court was
required by M.R.C.P. 15(a), such amendment is improper and the amended pleading will be struck. See D.P. Holmes Trucking, LLC v. Butler, 94 So. 3d 248, 255 (Miss. 2012).
An amended complaint that adds additional defendants must also comply with M.R.C.P. 21. See Veal v. J.P. Morgan Tr. Co., N.A., 955 So. 2d 843, 847 (Miss. 2007) (“Where . . . the amendment sought is to add new defendants, Mississippi Rule of Civil Procedure 21 is applicable, and requires an order from the court to add a new defendant”).
An amended pleading adding a new claim or defense among existing parties relates back to the original pleading when the claim or defense in the amended pleading arises from the same conduct, transaction or occurrence set forth in the original pleading.
An amended pleading changing the name of the defending party relates back to the original pleading if the requirements of M.R.C.P. 15(c)(1) and (2) are met.
An amendment substituting a named party for a fictitious party pursuant to M.R.C.P. 9(h) relates back only if the plaintiff exercised reasonable diligence to discover the true identity of the fictitious party. See Bedford Health Properties, LLC v. Estate of Williams ex rel Hawthorne, 946 So. 2d 335, 342 (Miss. 2006).
An amended pleading adding an additional defendant does not relate back to the original pleading unless: (i) it is an amendment changing the defending party’s name and the requirements of M.R.C.P. l5(c)(1) and (2) are met; or (ii) is an amendment substituting a named defendant for a fictitious defendant pursuant to M.R.C.P. 9(h) and the reasonable diligence standard is met.
Amendment History
Effective July 1, 1998, Rule 15(c) was amended to state that the relation back period includes the time permitted for service of process under Rule 4(h).
Effective July 1, 2020, the subsections within Rule 15 (c) were reorganized and renumbered.
Plain-English Summary
Rule 15(a) draws the line between amending as a matter of right and amending by permission. A party may amend before any responsive pleading is served, or, if none is required and the case hasn't reached the trial calendar, within 30 days after the pleading was served. The official Notes point out a real difference from federal practice: the federal rule allows only one amendment as of course, while Mississippi's places no limit on the number of such amendments. After that window, amendment requires either leave of court — to be given freely when justice requires — or the other side's written consent. When a Rule 12(b)(6) or Rule 12(c) motion succeeds, leave to amend must be granted as justice requires, provided the motion was decided on the pleadings alone. A response to an amended pleading is due within whichever is longer: the time remaining to respond to the original pleading, or 10 days after the amendment is served.
Rule 15(b) handles issues that come up at trial without having been pleaded. If the parties try an unpleaded issue by express or implied consent, it's treated as if it had been raised in the pleadings all along, and the pleadings can be amended to match the evidence — even after judgment — though failing to amend doesn't change the outcome of what was tried. If a party objects that evidence falls outside the pleaded issues, the court can still allow an amendment when it would serve the merits and the objecting party can't show real prejudice, and it can grant a continuance to let that party respond to the new evidence.
Rule 15(c) governs when an amendment relates back to the date of the original pleading rather than the later date of the amendment — a distinction that can decide whether a claim survives a statute of limitations. An amendment relates back whenever it arises from the same conduct, transaction, or occurrence already set out, or attempted to be set out, in the original pleading. An amendment that changes the party being sued relates back on the same condition, plus two more: within the period Rule 4(h) allows for service, the new party must have had enough notice of the suit to avoid prejudice in defending it, and must have known or should have known that, but for a mistake about identity, the suit would have named it. A fictitious-party amendment under Rule 9(h) isn't treated as changing the party at all, and always relates back — though the official Notes caution that this only works if the plaintiff used reasonable diligence to discover the fictitious party's true identity, and that an amendment adding a defendant not previously named must also satisfy Rule 21. Rule 15(d) rounds out the rule by letting a party add a supplemental pleading, with the court's permission, covering events that happened after the original pleading — allowed even if that original pleading was itself defective, and the court can order the other side to respond to it.
Frequently Asked Questions
How many times can I amend my pleading without asking the court's permission?
Mississippi's rule sets no limit, unlike the federal rule, which allows only one amendment as of course. Rule 15(a) lets you amend as many times as you like before a responsive pleading is served, or within 30 days after your own pleading was served if no response is required.
When does an amendment "relate back" to my original filing date?
Under Rule 15(c)(1), an amendment relates back whenever it arises from the same conduct, transaction, or occurrence already set out, or attempted to be set out, in the original pleading — a distinction that matters most when a statute of limitations has run in the meantime.
Can I amend to add a new defendant after the statute of limitations has already run?
It's possible under Rule 15(c)(2), if the same-transaction test is met and, within the period Rule 4(h) allows for service, the new party had notice enough to avoid prejudice and knew or should have known the suit would have named it but for a mistake about identity. The official Notes add that an amendment adding a new defendant not previously named must also comply with Rule 21.
What happens if evidence outside the pleadings comes in at trial without objection?
Rule 15(b) treats an issue tried by the parties' express or implied consent as if it had been raised in the pleadings from the start. The pleadings can be amended to match that evidence at any time, even after judgment, though failing to amend doesn't affect the result of what was tried.
Can I add facts to my pleading about events that happened after I filed it?
Yes, through a supplemental pleading under Rule 15(d), with the court's permission and on reasonable notice. That's allowed even if the original pleading was itself defective, and the court can require the other side to respond to the new material.
Source & verification. Rule text and Advisory Committee Notes are
reproduced verbatim from the Mississippi Rules of Civil Procedure, adopted by the
Supreme Court of Mississippi. Last verified July 14, 2026.
· Official source
Also known as: ms rule 15 amended pleadingsrelation back amendment mississippiamend complaint after statute of limitations mssupplemental pleading mississippi ruleadding a new defendant relation back ms