FEDERAL RULES OF CIVIL PROCEDURE
Articles III-Rule 15

FEDERAL RULES OF CIVIL PROCEDURE

ARTICLE III-PLEADINGS AND MOTIONS

Rule 15. Amended and Supplemental Pleadings

(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 the
party's 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 foregoing provision (2) is satisfied and, within
the period provided by Rule 4(m) 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.

The delivery or mailing of process to the United States Attorney, or United
States Attorney's designee, or the Attorney General of the United States, or an
agency or officer who would have been a proper defendant if named, satisfies
the requirement of subparagraphs (A) and (B) of this paragraph (3) with
respect to the United States or any agency or officer thereof to be brought into
the action as a defendant.

(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.
 

Federal Rules of Civil Procedure Articles III  Rule Rule 15. Amended and Supplemental Pleadings: Notes

Federal Rules of Civil Procedure Articles II Rule 4. Summons-LII
Notes: Rule 1. Scope and Purpose of Rules
Federal Civil Procedure-Volume-56-Table of Contents   
Articles III PLEADINGS AND MOTIONS-Table of Contents-Links To LII  
Federal Rules of Civil Procedure Articles III: Rule 13. Counterclaim and Cross-Claim
  Amended and Supplemental Pleadings