M.R. Civ. P. 15

(a) Amendments. A party may amend the party’s 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 20 days after it is served. Otherwise a party may amend the party’s

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 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. 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 party in maintaining an action or defense upon the merits. The court may

grant a continuance to enable the objecting party to meet such evidence.

(c) Relation Back of Amendments. An amendment of a pleading relates

back to the date of the original pleading when

(1) relation back is permitted by the law that provides the statute

of limitations applicable to the action, or

(2) 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, or

(3) the amendment changes the party or the naming of the party

against whom a claim is asserted if the condition of paragraph (2) of this

subdivision is satisfied and, within the period provided by Rule 3 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 a 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.

(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 or 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.