Idaho R. Fam. L.P. 216

(a) When an Amendment Relates Back. An amendment to a pleading relates back to the date of the original pleading when:

(1) the law that provides the applicable statute of limitations allows relation back;

(2) the amendment asserts a claim or defense that arose out of the conduct, transaction, or occurrence set out, or attempted to be set out, in the original pleading; or

(3) the amendment changes the party or the naming of the party against whom a claim is asserted, if subsection(a)(2) is satisfied and if, within the period provided by Rule 204(b) for serving the summons and petition, the party to be brought in by amendment:

(A) received such notice of the action that it will not be prejudiced in defending on the merits; and

(B) knew or should have known that the action would have been brought against it, but for a mistake concerning the proper party's identity.

(b) Notice to the State. When the state of Idaho or any agency or officer of the state is added as a defendant by amendment, the notice requirements of subsections (a)(3)(A) and

(B) are satisfied if, during the stated period, process was delivered or mailed to the Idaho attorney general or designee of the attorney general, or to the officer or agency.

(c) Joining Real Party in Interest. The relation back of an amendment joining or substituting a real party in interest is as provided in Rule 202.