(1) PERSONS TO BE JOINED IF FEASIBLE. A person who is subject to service of process shall be joined as a party in the action if: (a) In the person's absence complete relief cannot be accorded among those already parties; or(b) The person claims an interest relating to the subject of the action and is so situated that the disposition of the action in the person's absence may: 1. As a practical matter impair or impede the person's ability to protect that interest; or2. Leave any of the persons already parties subject to a substantial risk of incurring double, multiple or otherwise inconsistent obligations by reason of his or her claimed interest.(2) CLAIMS ARISING BY SUBROGATION, DERIVATION AND ASSIGNMENT. (a)Joinder of related claims. A party asserting a claim for affirmative relief shall join as parties to the action all persons who at the commencement of the action have claims based upon subrogation to the rights of the party asserting the principal claim, derivation from the principal claim, or assignment of part of the principal claim. For purposes of this section, a person's right to recover for loss of consortium shall be deemed a derivative right. Any public assistance recipient or any estate of such a recipient asserting a claim against a 3rd party for which the public assistance provider has a right of subrogation or assignment under s. 49.89(2) or (3) shall join the provider as a party to the claim. Any party asserting a claim based upon subrogation to part of the claim of another, derivation from the rights or claim of another, or assignment of part of the rights or claim of another shall join as a party to the action the person to whose rights the party is subrogated, from whose claim the party derives his or her rights or claim, or by whose assignment the party acquired his or her rights or claim.(b)Options after joinder.1. Any party joined pursuant to par. (a) may do any of the following: a. Participate in the prosecution of the action.b. Agree to have his or her interest represented by the party who caused the joinder.c. Move for dismissal with or without prejudice.2. If the party joined chooses to participate in the prosecution of the action, the party joined shall have an equal voice with other claimants in the prosecution.3. Except as provided in par. (bm), if the party joined chooses to have his or her interest represented by the party who caused the joinder, the party joined shall sign a written waiver of the right to participate that shall express consent to be bound by the judgment in the action. The waiver shall become binding when filed with the court, but a party may withdraw the waiver upon timely motion to the judge to whom the case has been assigned with notice to the other parties. A party who represents the interest of another party and who obtains a judgment favorable to the other party may be awarded reasonable attorney fees by the court.4. If the party joined moves for dismissal without prejudice as to his or her claim, the party shall demonstrate to the court that it would be unjust to require the party to prosecute the claim with the principal claim. In determining whether to grant the motion to dismiss, the court shall weigh the possible prejudice to the movant against the state's interest in economy of judicial effort.(bm)Joinders because of implication of medical assistance. If the department of health services is joined as a party pursuant to par. (a) and s. 49.89(2) because of the provision of benefits under subch. IV of ch. 49, the department of health services need not sign a waiver of the right to participate in order to have its interests represented by the party that caused the joinder. If the department of health services makes no selection under par. (b), the party causing the joinder shall represent the interests of the department of health services and the department of health services shall be bound by the judgment in the action.(c)Scheduling and pretrial conferences. At the scheduling conference and pretrial conference, the judge to whom the case has been assigned shall inquire concerning the existence of and joinder of persons with subrogated, derivative or assigned rights and shall make such orders as are necessary to effectuate the purposes of this section. If the case is an action to recover damages based on alleged criminally injurious conduct, the court shall inquire to see if an award has been made under subch. I of ch. 949 and if the department of justice is subrogated to the cause of action under s. 949.15 .(3) DETERMINATION BY COURT WHENEVER JOINDER NOT FEASIBLE. If any such person has not been so joined, the judge to whom the case has been assigned shall order that the person be made a party. If the person should join as a plaintiff but refuses to do so, the person may be made a defendant, or, in a proper case, an involuntary plaintiff. If a person as described in subs. (1) and (2) cannot be made a party, the court shall determine whether in equity and good conscience the action should proceed among the parties before it, or should be dismissed, the absent person being thus regarded as indispensable. The factors to be considered by the court include: (a) To what extent a judgment rendered in the person's absence might be prejudicial to the person or those already parties;(b) The extent to which, by protective provisions in the judgment, by the shaping of relief, or other measures, the prejudice can be lessened or avoided;(c) Whether a judgment rendered in the person's absence will be adequate; and(d) Whether the plaintiff will have an adequate remedy if the action is dismissed for nonjoinder.(4) PLEADING REASONS FOR NONJOINDER. A pleading asserting a claim for relief shall state the names, if known to the pleader, of any persons as described in subs. (1) and (2) who are not joined, and the reasons why they are not joined.(5) EXCEPTION OF CLASS ACTIONS. This section is subject to s. 803.08 .Sup. Ct. Order, 67 Wis. 2d 585, 643 (1975); 1975 c. 218; 1979 c. 189, 221; 1983 a. 192; 1985 a. 29; 1989 a. 31; 1995 a. 27; 1997 a. 35; 1999 a. 9; 2001 a. 103; 2005 a. 253; 2007 a. 20 ss. 3752, 9121 (6) (a). When the constitutionality of a statute is challenged in an action other than a declaratory judgment action, the attorney general must be served, but failure to do so at the trial level was cured by service at the appellate level. In Matter of Estate of Fessler, 100 Wis. 2d 437, 302 N.W.2d 414 (1981). Sub. (2) (b) requires a subrogated party to choose one of the listed options or risk dismissal with prejudice. Radloff v. General Casualty Co., 147 Wis. 2d 14, 432 N.W.2d 597 (Ct. App. 1988). The mere presence of a party does not constitute "participation" under sub. (2) (b). A subrogated insurer who exercises none of the three options under sub. (2) (b) must pay its fair share of attorney fees and costs if it has notice of and does nothing to assist in the prosecution of the action. Ninaus v. State Farm Mutual Automobile Insurance Co., 220 Wis. 2d 869, 584 N.W.2d 545 (Ct. App. 1998), 97-0191. Failure to comply with the technical requirement under sub. (2) (b) that a joined party must file a written waiver of the right to participate in the trial does not prevent the joined party's assertion that it had a representation agreement with the joining party. Gustafson v. Physicians Insurance Co., 223 Wis. 2d 164, 588 N.W.2d 363 (Ct. App. 1998), 97-3832. Whether a party is an "indispensable party" requires a two-part inquiry. First, it must be determined if the party is "necessary" for one of the three reasons under sub. (1). If not, the party cannot be "indispensable" under sub. (3). If the party is found necessary, then, whether "in equity and good conscience" the action should not proceed in the absence of the party must be determined. Dairyland Greyhound Park, Inc. v. McCallum, 2002 WI App 259, 258 Wis. 2d 210, 655 N.W.2d 474, 02-1204. If a person has no right of intervention under s. 803.09(1), the courts have no duty to join that person sua sponte as a necessary party under sub. (1) (b) 1. The inquiry of whether a movant is a necessary party under sub. (1) (b) 1. is in all significant respects the same inquiry under s. 803.09(1) as to whether a movant is entitled to intervene in an action as a matter of right, including the requirement that the interest of the movant is adequately represented by existing parties. A movant who fails to meet that requirement for intervention as of right may not simply turn around and force its way into the action by arguing that the court must join the movant, sua sponte, as a necessary party under sub. (1) (b) 1. Helgeland v. Wisconsin Municipalities, 2008 WI 9, 307 Wis. 2d 1, 745 N.W.2d 1, 05-2540. If the plaintiff was required to join a party holding a constituent part of a cause of action under sub. (2) (a) but failed to do so, then the unjoined subrogation, derivative, or assigned claims were deemed timely when made by the other party by virtue of the s. 802.09(3) relation-back doctrineas long as such claims were asserted in the original action. However, if the plaintiff was not required to join the other party's cause of action under sub. (2) (a)i.e., the other party's claims did not arise by subrogation, derivation, or assignment, and therefore were not part of the plaintiff's claim in chiefthe other party's claims do not relate back to the date of the original filing and are time-barred. Town of Burnside v. City of Independence, 2016 WI App 94, 372 Wis. 2d 802, 889 N.W.2d 186, 16-0034.