15.01 Amendments A party may amend a 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 upon the trial calendar, the party may so amend it no later than 21 days after it is served. Otherwise a party may amend a pleading only by leave of court or by written consent of the adverse party; and 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 14 days after service of the amended pleading, whichever period may be longer, unless the court otherwise orders.
Rule 15.Amended and Supplemental Pleadings
Last amended January 1, 2025 · Last verified July 1, 2026
In one sentenceRule 15 lets a party fix, expand, or update its pleadings as the case develops, sometimes without asking the court’s permission first.
Full Text of Rule 15
15.02 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. 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 a trial of these issues. If evidence is objected to at the trial on the ground that it is not within the issues raised 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 admission of such evidence would prejudice maintenance of the action or defense upon the merits. The court may grant a continuance to enable the objecting party to meet such evidence.
15.03 Relation Back of Amendments 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. 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 law for commencing the action against the party, the party to be brought in by amendment (1) has received such notice of the institution of the action that the party will not be prejudiced in maintaining a defense on the merits, and (2) knew or should have known that, but for a mistake concerning the identity of the proper party, the action would have been brought against that party.
15.04 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, whether or not the original pleading is defective in its statement of a claim for relief or of a defense. If the court deems it advisable that the adverse party plead thereto, it shall so order, specifying the time therefor.
Advisory Committee Comments
Advisory Committee Comment—2025 Amendment
Rule 15.01 is amended in 2025 to clarify that 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 amend it as a matter of course no later than 21 days after it is served.
Amendment History
- (Amended effective January 1, 2025.)
Plain-English Summary
Lawsuits rarely stay exactly as they were first described in the complaint or answer. Rule 15 gives parties a path to change what they have filed. Early in a case, a party can amend a pleading once without asking anyone’s permission — before the other side has responded, or within 21 days after filing if no response is required and the case has not reached the trial calendar. After that window closes, a party needs either the court’s permission or the other side’s written agreement, and courts are supposed to grant that permission freely when fairness calls for it.
The rule also covers what happens when the evidence at trial strays from what the pleadings described. If both sides go along with proof on an issue that was not formally pleaded, the court treats that issue as if it had been raised from the start. Even an objection to unpled evidence does not necessarily stop it — the court can allow the pleadings to be amended on the spot, and must do so freely when it would help resolve the case on the merits and the objecting side cannot show real prejudice. The judge can also pause the trial to give the surprised party time to respond to the new evidence.
A trickier issue arises when an amendment adds a new claim or changes who is being sued after a deadline (like a statute of limitations) has passed. Rule 15 allows the amendment to “relate back” to the date of the original filing — treated as if it had been filed on time — as long as the new claim grew out of the same underlying events, and, when a party is being swapped in, that party had notice of the lawsuit and knew or should have known the suit was really meant for them.
Finally, the rule addresses supplemental pleadings: filings that describe things that happened after the original pleading was filed, distinct from corrections to what was already said. A party needs the court’s permission for these, and the court sets fair terms for how the other side responds.
Frequently Asked Questions
How long do I have to amend my complaint without asking the court?
You can amend once as a matter of course before the other side files a response, or, if no response is required and the case is not on the trial calendar yet, no later than 21 days after you served the pleading.
What if I want to amend after that window closes?
You need either the court’s permission or the other party’s written consent; the rule directs courts to grant permission freely when justice requires it.
If I add a new defendant after the statute of limitations has run, is my claim automatically too late?
Not necessarily. The amendment can relate back to the original filing date if it arises from the same conduct or events, and the new party had notice of the suit and knew or should have known the case was meant for them, but for a mistake about identity.
How much time do I get to respond to an amended pleading?
You must respond within whatever time was left to respond to the original pleading, or within 14 days after the amended pleading is served, whichever period is longer, unless the court orders otherwise.
What is the difference between an amended pleading and a supplemental pleading?
An amendment corrects or changes what is already been pleaded; a supplemental pleading adds new transactions or events that happened after the original pleading was filed, and it always requires the court’s permission.
Source & verification. The rule text and Advisory Committee Comments are reproduced verbatim from the
official Minnesota Rules of Civil Procedure (Minn. R. Civ. P. 15). Prescribed by the Supreme Court of Minnesota (Minn. Stat. § 480.051). The plain-English summary is original and written by us. Last verified July 1, 2026. ·
Official source
Also known as: amended complaint rulerelation back rule
Advisory Committee Comment—2020 Amendments
Rule 15.01 is amended as part of the amendments made to the timing provisions of the rules. These amendments implement the adoption of a standard “day” for counting deadlines under the rules—counting all days regardless of the length of the period and standardizing the time periods, where practicable, to a 7-, 14-, 21- or 28-day schedule. The only changes to this rule lengthen the 20-day limit to 21 days, and the 10-day limit to 14 days. These change only the time limits, and are not intended to have any other effect.