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 at any time within 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.
(Amended effective January 1, 2020.)
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.
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.
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.