               IN THE SUPREME COURT OF IOWA
                            No. 82 / 05-0493

                         Filed December 1, 2006


WINNEBAGO INDUSTRIES, INC. and SENTRY INSURANCE,

      Appellees,

vs.

MARK HAVERLY,

      Appellant.


      On review from the Iowa Court of Appeals.



      Appeal from the Iowa District Court for Polk County, Robert A.

Hutchison, Judge.



      Claimant in workers’ compensation case won a favorable ruling from

the Workers’ Compensation Commissioner, but the ruling was reversed by

the district court. The claimant appealed, the court of appeals affirmed,

and we granted further review.       DECISION OF COURT OF APPEALS

VACATED; JUDGMENT OF DISTRICT COURT REVERSED; CASE

REMANDED.



      Christopher D. Spaulding of Berg, Rouse, Spaulding & Schmidt,

P.L.C., Des Moines, for appellant.



      Lee P. Hook and Joseph M. Barron of Peddicord, Wharton, Spencer &

Hook, LLP, Des Moines, for appellees.
                                             2

LARSON, Justice.

       Mark Haverly, who was employed by Winnebago Industries, Inc., filed

a workers’ compensation claim under Iowa Code chapter 85 (2001) and won

a favorable ruling from the Workers’ Compensation Commissioner. On

judicial review, however, the district court reversed the commissioner’s

ruling, and the court of appeals affirmed. On further review, we vacate the

decision of the court of appeals, reverse the judgment of the district court,

and remand.

       I. Facts and Prior Proceedings.

       Mark Haverly began working for Winnebago in 1983. In 1992 he

suffered a work-related back injury and, in 1997, entered into a settlement

of his workers’ compensation claim. Winnebago provided ongoing medical

care for this back injury.          Haverly continued to have back pain and

underwent various courses of treatment, including surgery.                              On

November 7, 2000, Haverly went to a doctor complaining of increased back

pain, and the doctor recommended conservative treatment. Dissatisfied

with the subsequent care provided by Winnebago, Haverly sought medical

care from Dr. David Beck in February 2002.                    Dr. Beck recommended

surgery. This surgery, however, was not authorized by Winnebago.
       In March 2002 Haverly filed a petition for workers’ compensation

benefits, alleging that a work-related back injury occurred on November 7,

2000. 1 Winnebago responded that any injury sustained on November 7,
2000, related to Haverly’s 1992 injury and, at most, caused a temporary

aggravation of his preexisting back condition.

       Because Winnebago did not authorize Haverly to proceed with the

surgery recommended by Dr. Beck, Haverly filed an application for alternate

       1Haverlyalso filed a petition alleging that he suffered a work-related back injury on
March 2, 2000. This alleged injury is not at issue on further review.
                                     3

medical care on May 17, 2002. See Iowa Code § 85.27; Iowa Admin. Code r.

876—4.48.    This petition alleged a November 7, 2000 injury date and

requested that the surgery be provided by Winnebago. Haverly supported

his request with an opinion from Dr. Beck that Haverly’s work duties had

aggravated his preexisting back condition and that surgery was necessary.

Winnebago filed an answer to the request for alternate medical care but, in

its answer, did not dispute liability for the November 7 work injury. (A box

on the answer form stating “employer denies [the claimant’s allegation of

liability]” was not checked by Winnebago’s attorney.) Moreover, at the

hearing on the application for alternate care, Winnebago’s attorney

confirmed that Winnebago was not disputing liability for the injury. A

deputy commissioner granted Haverly’s application for alternate care and

ordered Winnebago to provide the surgery. Agency rules provide no intra-

agency appeal from such orders, and Winnebago did not seek judicial

review.

      Haverly’s claim for benefits proceeded to a hearing in 2003. The

deputy commissioner determined, in relevant part, that the issue of liability

for the November 7 injury had been previously “litigated” in the alternate-

medical-care proceeding and that this prior decision was, therefore,
res judicata on the issue of liability. The deputy stated:

      [I]njury arising out of and in the course of employment has
      been established in a prior contested case proceeding entitled
      to the same preclusive effect as is this arbitration proceeding.

Winnebago appealed the arbitration decision on this and several other

grounds.    On the intra-agency appeal, the Workers’ Compensation

Commissioner affirmed the deputy’s conclusion that Winnebago’s admission

of liability in the alternate-medical-care proceeding was res judicata on the

issue of liability for benefits. The commissioner also ruled that, even if
                                          4

issue preclusion did not prevent Winnebago from litigating the issue, the

record “amply demonstrates” that Haverly suffered a new injury on

November 7, 2000.

      Winnebago      sought    judicial       review,   challenging   the   agency’s

res judicata determination, as well as the existence of a new injury. The

district court reversed, ruling that issue preclusion did not apply because

the issue of liability had not been “raised and litigated” in the prior action.

See United Fire & Cas. Co. v. Shelly Funeral Home, Inc., 642 N.W.2d 648,

655 (Iowa 2002). The district court found that Winnebago’s admission of

liability in the alternate-medical-care proceeding was an admission of

liability for medical care only and not an admission of liability for a new

injury.

      On appeal, the court of appeals affirmed.              The court noted, but

rejected, Haverly’s complaint that the district court’s conclusion permitted

Winnebago to admit liability for the purpose of controlling medical care, but

then deny it for the purpose of determining compensability. The court

concluded that the requirements for issue preclusion were not met and that

neither law-of-the-case nor judicial-estoppel doctrines could be applied to

bar litigation of the liability issue.
      Haverly contends Winnebago should not be permitted to admit

liability in the alternate-medical-care proceeding when that worked to its

advantage (by allowing Winnebago to control Haverly’s medical care) and

then reverse its position in the arbitration hearing on the issue of liability

for benefits. The arbitration decision stated a similar view of the case and

questioned Winnebago’s motives in admitting liability in the alternate-

medical-care proceeding. That decision observed

      that, under 876 I.A.C. 4.48(7), the expedited procedure [for
      alternate medical care] is not available where liability is
      disputed. Indeed, [Winnebago] filed a formal answer admitting
                                       5
      liability on May 29, 2002. At the beginning of the hearing,
      [Winnebago’s] attorney was asked directly whether liability was
      admitted, and answered just as directly that it was. . . .
             The decision in that case [on alternate medical care]
      constitutes final agency action and has not been appealed.
      [Winnebago], however, ha[s] experienced a change of heart and
      now seek[s] to dispute liability. In agency experience, it is not
      unheard of for certain employers and insurance carriers to
      “admit” liability when there is something to gain thereby (the
      right to control medical treatment), yet thereafter attempt to
      deny liability as to the case in chief. This litigation offers a
      classic example.

      On Winnebago’s intra-agency appeal, the commissioner made a

similar observation. While the commissioner did not identify the doctrine of

judicial estoppel by name, he clearly stated the gist of it in this language:

              It would be patently unfair to allow an employer to admit
      liability and control the medical care for a medical condition
      and then allow that employer, after the care is completed to
      deny liability and litigate the liability issue, unless there are
      good reasons for doing so.

      II. The Issues.

      Haverly raises a single issue: whether Winnebago is foreclosed from

denying its liability for the November 7, 2000 injury by admitting its liability

in the earlier alternate-medical-care proceeding. He raises three arguments

in support of his appeal: issue preclusion, law of the case, and judicial

estoppel.

      III. Standard of Review.

      Judicial review of a workers’ compensation decision by the

commissioner is governed by Iowa Code chapter 17A, our Administrative

Procedure Act. See Iowa Code § 86.26. A party challenging agency action

bears the burden of proving both the invalidity of the agency’s action and

resulting prejudice.    Iowa Code § 17A.19(8)(a); Hill v. Fleetguard, 705

N.W.2d 665, 671 (Iowa 2005).
                                      6

      When a district court exercises its authority on judicial review, it acts

in an appellate capacity to correct any errors of law by the agency. Hill, 705

N.W.2d at 669; Heartland Express, Inc. v. Terry, 631 N.W.2d 260, 265 (Iowa

2001). The district court may reverse, modify, or grant other appropriate

relief if substantial rights of the petitioner have been prejudiced. Hill, 705

N.W.2d at 669; Heartland Express, Inc., 631 N.W.2d at 265.

      On our review of the district court’s decision, we apply the standards

of chapter 17A to determine if our conclusions are the same as those of the

district court. If so, we affirm; otherwise, we reverse or otherwise modify.

Hill, 705 N.W.2d at 669.

      IV. Issue Preclusion.

      Haverly argues, and the commissioner ruled, that the issue of

Winnebago’s liability for the November 7 claim had been decided in the

proceeding on Haverly’s application for alternate medical care because

Winnebago conceded the point in its answer. Based on the principle of

issue preclusion, the agency refused to revisit the issue of liability.

      The doctrine of res judicata includes both claim preclusion and issue

preclusion. Colvin v. Story County Bd. of Review, 653 N.W.2d 345, 348

(Iowa 2002). In this case, Haverly relies on issue preclusion, also known as
collateral estoppel. See Hunter v. City of Des Moines, 300 N.W.2d 121, 123

n.2 (Iowa 1981). Under issue preclusion, once a court has decided an issue

of fact or law necessary to its judgment, the same issue cannot be

relitigated in later proceedings. Id. at 123. Issue preclusion serves a dual

purpose: to protect litigants from “the ‘vexation of relitigating identical

issues with identical parties or those persons with a significant connected

interest to the prior litigation,’ ” and to further “the interest of judicial

economy and efficiency by preventing unnecessary litigation.” Am. Family

Mut. Ins. Co. v. Allied Mut. Ins. Co., 562 N.W.2d 159, 163 (Iowa 1997)
                                       7

(quoting State ex rel. Casas v. Fellmer, 521 N.W.2d 738, 740-41 (Iowa

1994)). Under our four-part test, the doctrine applies to prevent relitigation

if:

      (1) the issue determined in the prior action is identical to the
      present issue; (2) the issue was raised and litigated in the prior
      action; (3) the issue was material and relevant to the
      disposition in the prior action; and (4) the determination made
      of the issue in the prior action was necessary and essential to
      that resulting judgment.

United Fire & Cas. Co., 642 N.W.2d at 655.

      The element of issue preclusion of concern in this case is whether the

issue of Winnebago’s liability was “raised and litigated” in the alternate-care

proceeding. Iowa law is clear that issue preclusion requires that the issue

was “actually litigated” in the prior proceeding.        Spiker v. Spiker, 708

N.W.2d 347, 353 (Iowa 2006); Hoth v. Iowa Mut. Ins. Co., 577 N.W.2d 390,

391-92 (Iowa 1998); see also Restatement (Second) of Judgments § 27

(“When an issue of fact or law is actually litigated and determined by a valid

and final judgment, and the determination is essential to the judgment, the

determination is conclusive in a subsequent action between the parties,

whether on the same or a different claim.”).

             An issue is not actually litigated if the defendant might
      have interposed it as an affirmative defense but failed to do so;
      nor is it actually litigated if it is raised by a material allegation
      of the party’s pleading but is admitted (explicitly or by virtue of
      a failure to deny) in a responsive pleading; nor is it actually
      litigated if it is raised in an allegation by one party and is
      admitted by the other before evidence on the issue is adduced
      at trial; nor is it actually litigated if it is the subject of a
      stipulation between the parties. A stipulation may, however,
      be binding in a subsequent action between the parties if the
      parties have manifested an intention to that effect.
      Furthermore, under the rules of evidence applicable in the
      jurisdiction, an admission by a party may be treated as
      conclusive or be admissible in evidence against that party in a
      subsequent action.
            In the case of a judgment entered by confession, consent,
      or default, none of the issues is actually litigated. Therefore,
                                      8
      the rule of this Section does not apply with respect to any issue
      in a subsequent action. The judgment may be conclusive,
      however, with respect to one or more issues, if the parties have
      entered an agreement manifesting such an intention.

Restatement (Second) of Judgments § 27 cmt. e; see also United States v.

Young, 804 F.2d 116, 118 (8th Cir. 1986) (“A fact established in prior

litigation not by judicial resolution but by stipulation has not been ‘actually

litigated’ and thus is the proper subject of proof in subsequent

proceedings.”); 50 C.J.S. Judgments § 813, at 381 (1997) (“Facts determined

by admissions and stipulations ordinarily are not entitled to collateral

estoppel effect, because facts so determined are not actually litigated,

unless the parties to the stipulation manifest an intent to be bound in a

subsequent action.” (Footnotes omitted.)).

      We agree with the court of appeals and the district court that

Winnebago’s admission of liability in the alternate-care proceeding did not

constitute actual litigation for the purpose of applying issue preclusion.

      V. Law of the Case.

      Haverly also argues that the deputy commissioner’s order requiring

Winnebago to furnish alternate medical care is binding in future

proceedings on that claim. “The doctrine of the law of the case represents

the practice of courts to refuse to reconsider what has once been decided.”

State v. Grosvenor, 402 N.W.2d 402, 405 (Iowa 1987); accord State ex rel.

Goettsch v. Diacide Distrib., Inc., 596 N.W.2d 532, 537 (Iowa 1999).

Pursuant to this principle,

      legal principles announced and the views expressed by a
      reviewing court in an opinion, right or wrong, are binding
      throughout further progress of the case upon the litigants, the
      trial court and this court in later appeals.

Grosvenor, 402 N.W.2d at 405; 5 Am. Jur. 2d Appellate Review § 605, at

300-01 (1995).
                                      9

      The answer to Haverly’s law-of-the-case argument is that the agency

did not decide anything as to Winnebago’s liability for compensation

benefits, but only his right to alternate care. In fact, for reasons we discuss

later, the agency could not decide liability at that stage. See Iowa Admin.

Code r. 876—4.48(7) (2001) (If liability is disputed, the application for

alternate medical care would have to be dismissed.). Our resolution of the

issue regarding Winnebago’s admission of liability in the alternate-care

proceeding is not based on what the agency did or decided at that point, but

what Winnebago did. As such, the law-of-the-case doctrine does not bar

Winnebago’s denial of liability in this case. That brings us to the issue of

judicial estoppel, Haverly’s third argument.

      VI. Judicial Estoppel.

      Haverly argues that Winnebago is judicially estopped from denying

liability for the November 7, 2000 injury because it conceded that issue in

the alternate-medical-care proceeding. In this case, Haverly did not raise

the issue of judicial estoppel. In fact, it was only mentioned and rejected by

the district court in its ruling on judicial review. However, because judicial

estoppel is intended to protect the integrity of the fact-finding process by

administrative agencies and courts, the issue may properly be raised by
courts, even at the appellate stage, on their own motion. See In re Cassidy,

892 F.2d 637, 641 (7th Cir. 1990); State v. Duncan, 710 N.W.2d 34, 43-44

(Iowa 2006).

      Under our cases,

      [t]he doctrine [of judicial estoppel] “prohibits a party who has
      successfully and unequivocally asserted a position in one
      proceeding from asserting an inconsistent position in a
      subsequent proceeding.” It is a “common sense” rule, designed
      to protect the integrity of the judicial process by preventing
      deliberately inconsistent—and potentially misleading—
      assertions from being successfully urged in succeeding
      tribunals. The doctrine is properly limited in its application to
                                       10
      cases involving privity with, or prejudice to, the party invoking
      the doctrine. Another fundamental feature of the doctrine is
      the requirement of proof that the inconsistent position has
      been successfully asserted in the prior tribunal. Without such
      proof, “application of the rule is unwarranted because no risk
      of inconsistent, misleading results exists.”

Wilson v. Liberty Mut. Group, 666 N.W.2d 163, 166 (Iowa 2003) (quoting

Vennerberg Farms, Inc. v. IGF Ins. Co., 405 N.W.2d 810, 814 (Iowa 1987))

(other citations omitted).

      The doctrine at issue, although called “judicial” estoppel, is applicable

in administrative, as well as judicial, cases. See Rissetto v. Plumbers &

Steamfitters Local 343, 94 F.3d 597, 604 (9th Cir. 1996).

            Unsurprisingly given its name, judicial estoppel is often
      articulated as applying to “judicial” proceedings. However,
      many cases have applied the doctrine where the prior
      statement was made in an administrative proceeding, and we
      are not aware of any case refusing to apply the doctrine
      because the prior proceeding was administrative rather than
      judicial.

Id.; see also Chaveriat v. Williams Pipe Line Co., 11 F.3d 1420, 1427 (7th Cir.

1993) (“Though called judicial estoppel, the doctrine has been applied,

rightly in our view, to proceedings in which a party to an administrative

proceeding obtains a favorable order that he seeks to repudiate in a

subsequent judicial proceeding.”); Charles Alan Wright, et al., Federal
Practice and Procedure § 4477, at 575 (2002) (judicial estoppel applicable to

cases of inconsistent statement made to administrative agency).             The

rationale for this principle is that “[a]scertaining the truth is as important in

an administrative inquiry as in judicial proceedings.” Simon v. Safelite

Glass Corp., 128 F.3d 68, 72 (2d Cir. 1997).

      Our Wilson case is closely analogous to this one. In Wilson a workers’

compensation claimant settled his case with his employer under the

provisions of Iowa Code section 85.35. As required by that statute, Wilson

admitted there was a bona fide dispute with his employer regarding the
                                      11

cause of his injury. His employer’s insurance carrier paid benefits under

the settlement agreement. Wilson then filed a lawsuit against the insurance

carrier for alleged bad-faith failure to settle the claim. Wilson, 666 N.W.2d

at 165.

      We held that Wilson was precluded, in a civil action, to claim bad-

faith failure to settle because this was exactly the opposite of what he had

stated in his workers’ compensation settlement agreement, i.e., that there

was a bona fide dispute on liability.      Id. at 166-67.   We reached that

conclusion on the basis of judicial estoppel because

      [p]lainly Wilson’s position in the bad faith action is inconsistent
      with the position he asserted in the workers’ compensation
      litigation. To prevail on his bad faith claim, Wilson would
      necessarily have to prove that Liberty Mutual had no
      reasonable basis to deny his claim. Yet in the section 85.35
      proceedings before the workers’ compensation commissioner,
      Wilson successfully asserted there was a bona fide dispute as
      to whether his injuries were work-related so as to entitle him to
      additional benefits. These positions are clearly inconsistent.

Id. at 167 (citation omitted).

      In Simon a worker told the Social Security Administration he was

unable to work, and the court held he was judicially estopped from later

claiming damages for age discrimination against his employer because his

later claim required proof that he was qualified and able to perform the

duties required for his position. 128 F.3d at 73-74.

      In DeGuiseppe v. Village of Bellwood, 68 F.3d 187 (7th Cir. 1995), a

police officer won a disability pension by claiming inability to perform his

duties. He later sued the village for retaliatory discharge. As part of his

retaliatory-discharge suit, the plaintiff was required to show he was not

disabled. DeGuiseppe, 68 F.3d at 191. While the plaintiff contended he was

not disabled, the court said:
                                      12
      Regardless of whether or not this contention is true, this Court
      is not disposed to consider it. Under the doctrine of judicial
      estoppel, which “prevents a party who has successfully taken a
      position in one litigation from taking the opposite position in a
      subsequent litigation,” courts are under no compulsion to heed
      the shifting theories of “chameleonic litigants.” Instead, we will
      accept a party's prevailing position in previous litigation (or, as
      here, quasi-judicial proceedings) as dispositive.

Id. (quoting Czajkowski v. City of Chicago, 810 F. Supp. 1428, 1434 (N.D. Ill.

1992)) (other citation omitted).

      In this case, it is understandable why Winnebago admitted liability in

the alternate-care proceeding. If an employer admits liability, it ordinarily

has the right to control the care provided to the employee. Iowa Code

§ 85.27(4). The right to control treatment, however, is lost if the employer

disputes liability. Trade Prof’ls, Inc. v. Shriver, 661 N.W.2d 119, 124 (Iowa

2003). In Trade Professionals we based this conclusion on the Workers’

Compensation Commissioner’s interpretation of an administrative rule.

Under the Iowa Administrative Code,

      [a]pplication cannot be filed under this rule [for applying for
      alternate care] if the liability of the employer is an issue. If an
      application is filed where the liability of the employer is at
      issue, the application will be dismissed without prejudice.

Iowa Admin. Code r. 876—4.48(7) (2001).
      As we noted in Trade Professionals,

      [t]he industrial commissioner has interpreted this section to
      mean that,
            in Iowa, an employer and its insurer have the right to
            control the medical care claimant receives, with two
            exceptions. The first is where the employer has denied
            liability for the injury. The second is where claimant has
            sought and received authorization from this agency for
            alternative medical care.

Trade Prof’ls, 661 N.W.2d at 124 (quoting Freels v. Archer Daniels Midland

Co., #1151214 (7/30/2000)).
                                    13

      We can assume in this case that Winnebago decided to admit liability

for the purpose of maintaining control over Haverly’s care, but rejected any

broader application of that admission because it wanted to challenge its

liability for payment of benefits. Under judicial estoppel, this ordinarily

cannot be permitted. There might, in some cases, be a significant change in

the facts after the admission of liability that could justify a change of

position by the employer, but those facts are not present here.

      VII. Conclusion.

      For the reasons discussed, we vacate the decision of the court of

appeals, reverse the judgment of the district court, and remand to the

commission for computation of benefits.

      DECISION OF COURT OF APPEALS VACATED; JUDGMENT OF

DISTRICT COURT REVERSED; CASE REMANDED.

      All justices concur except Hecht, J., who takes no part.
