No Waiver of Arbitration by Pre-Answer Rule 55.27(a)(6) Motion When Arbitration Is Timely Invoked as an Affirmative Defense

1) Introduction

Lange v. GMT Auto Sales, Inc. (Supreme Court of Missouri, en banc, March 18, 2025) addresses when a defendant waives its contractual right to arbitrate by litigating in court. The dispute arose from Connie Lange’s purchase of a fifth-wheel camping trailer from GMT Auto Sales, Inc. (“GMT”) in August 2020. GMT charged a $199 “administrative fee,” citing section 301.558, which authorizes such a fee in connection with the sale or lease of a “motor vehicle, vessel, or vessel trailer.”

Lange filed a putative class action alleging the fee violated the Missouri Merchandising Practices Act (“MMPA”) because a fifth-wheel camping trailer is not a “motor vehicle,” “vessel,” or “vessel trailer” under section 301.558. The retail installment contract contained an arbitration provision with a class-action waiver. GMT first filed a Rule 55.27(a)(6) motion to dismiss for failure to state a claim, then (six days after the motion was denied) moved to compel arbitration, and timely pleaded arbitration as an affirmative defense in its answer.

The circuit court compelled arbitration; the arbitrator awarded Lange $199 plus $5,000 in attorney fees and costs. Lange then sought to vacate, arguing (among other things) that GMT had waived arbitration by filing the motion to dismiss. The court of appeals agreed and reversed. The Supreme Court of Missouri granted transfer and ultimately affirmed confirmation of the arbitration award.

2) Summary of the Opinion

The Court resolved three appellate points:

  1. Waiver (Point II): GMT did not waive arbitration by filing a Rule 55.27(a)(6) motion to dismiss before moving to compel arbitration, where GMT moved to compel arbitration before filing its responsive pleading and pleaded arbitration as an affirmative defense.
  2. Assignment (Point I): GMT retained the right to compel arbitration even after assigning the retail installment contract, because the arbitration clause expressly covered disputes between Lange and GMT and “our employees, agent, successors or assigns.”
  3. Unconscionability / class waiver (Point III): Lange’s argument that the arbitration provision was unenforceable (because its class-action waiver was allegedly unenforceable and the clause purported to make the entire arbitration provision unenforceable if the class waiver failed) was not preserved and was not reviewed on appeal.

Holding in practical terms: Under Missouri’s ordinary waiver principles (as required by the FAA and Morgan v. Sundance, Inc.), filing a pre-answer motion to dismiss for failure to state a claim—followed by a prompt motion to compel arbitration and a timely pleading of arbitration as an affirmative defense—does not “clearly and unequivocally” relinquish the right to arbitrate.

3) Analysis

A) Precedents Cited (and how they shaped the decision)

1. Federal arbitration baseline: no arbitration-specific waiver rule

  • Morgan v. Sundance, Inc., 596 U.S. 411 (2022)
    The Court treated Sundance as the controlling framework: waiver occurs when a party knowingly acts inconsistently with the right to arbitrate, and courts must apply the “usual” procedural and waiver rules rather than arbitration-favoring “custom-made rules.” The majority used this to justify analyzing waiver under Missouri’s general contract waiver doctrine (not a heightened or arbitration-specific test, and not a prejudice requirement).
  • AT&T Mobility LLC v. Concepcion, 563 U.S. 333 (2011)
    Cited for the principle that the FAA preempts state-law doctrines applied “in a fashion that disfavors arbitration.” The majority invoked this to explain why waiver analysis must be the ordinary kind—neither tilted for nor against arbitration.

2. Missouri’s “clear and unequivocal” implied-waiver doctrine (the core rule applied)

  • Lucas Hunt Village Co. v. Klein, 218 S.W.2d 595 (Mo. banc 1949)
    Provides the canonical Missouri formulation: implied waiver requires conduct that “clearly and unequivocally” shows an intent to relinquish the right, “so manifestly consistent with and indicative of an intention to waive that no other reasonable explanation is possible.” The majority used this as the governing waiver standard under Sundance’s command to apply ordinary rules.
  • O'Connell v. Sch. Dist. of Springfield R-12, 830 S.W.2d 410 (Mo. banc 1992)
    Reinforces that implied waiver must be clear and unequivocal. The majority used this to reject the idea that a single Rule 55.27(a)(6) motion—followed quickly by invocation of arbitration—necessarily shows a purposeful relinquishment.

3. What a Rule 55.27(a)(6) motion is (and is not): not merits adjudication

  • Mo. State Conf. of NAACP v. State, 601 S.W.3d 241 (Mo. banc 2020) (quoting Mitchell v. Phillips, 596 S.W.3d 120 (Mo. banc 2020))
    The majority emphasized that a motion to dismiss for failure to state a claim “does not permit” courts to determine the merits; it tests only petition adequacy. This undercut the dissent’s characterization that GMT sought a merits judgment in a way inherently inconsistent with arbitration.
  • Bell v. Shelter Gen. Insur. Co., 701 S.W.3d 614 (Mo. banc 2024)
    Cited to stress that even legal questions can be premature at the motion-to-dismiss stage; the only inquiry is whether the plaintiff stated a cognizable claim. The majority used this to argue that GMT’s motion—whatever its prayer language—did not necessarily represent a decisive “choice” of judicial merits resolution over arbitration.
  • Mahoney v. Doerhoff Surgical Servs., Inc., 807 S.W.2d 503 (Mo. banc 1991)
    Used to support that dismissal with prejudice at the motion-to-dismiss stage is generally not the “greatest relief” available; this became part of the majority’s “multiple reasonable explanations” rationale (mistaken request for with-prejudice relief or mistaken procedural vehicle), which defeats a finding of clear and unequivocal waiver.
  • City of St. Louis v. State, 682 S.W.3d 387 (Mo. banc 2024) (citing Emerson Elec. Co. v. Marsh & McLennan Co., 362 S.W.3d 7 (Mo. banc 2012))
    Contrasts a motion to dismiss with a motion for judgment on the pleadings, which is merits-resolving. This distinction mattered because the majority treated GMT’s actual filing as non-merits in nature, weakening the inference of inconsistency with arbitration.

4. Arbitration as an affirmative defense and timely pleading mechanics

  • Dorris v. State, 360 S.W.3d 260 (Mo. banc 2012)
    Provided the definition of “affirmative defense.” The majority analogized the right to compel arbitration to a defense that avoids judicial liability by requiring a different forum.
  • GFS, II, LLC v. Carson, 684 S.W.3d 170 (Mo. App. 2023)
    Used to show Missouri appellate practice treating arbitration as an affirmative defense and associating failure to plead it with an intent to litigate.
  • Lopez v. GMT Auto Sales, Inc., 656 S.W.3d 315 (Mo. App. 2022)
    Provided an example of waiver through extensive litigation delay despite having pleaded arbitration. The majority used Lopez to distinguish this case: GMT moved to compel arbitration quickly (before its responsive pleading) and did not substantially litigate for months.
  • Gentry v. Orkin, LLC, 490 S.W.3d 784 (Mo. App. 2016)
    Used as another example where failure to plead arbitration in answers supported waiver.
  • Messina v. N. Cent. Distributing, Inc., 821 F.3d 1047 (8th Cir. 2016)
    Cited as consistent federal authority on waiver through failure to raise arbitration.
  • Johnson Assocs. Corp. v. HL Operating Corp., 680 F.3d 713 (6th Cir. 2012)
    Quoted for the proposition that the right to compel arbitration can operate as a “quasi-jurisdictional bar” supporting dismissal; the majority used it to justify classifying arbitration as an affirmative defense.

5. Preservation and plain error in civil cases

  • Brown v. Brown, 423 S.W.3d 784 (Mo. banc 2014)
    Anchored the preservation rule: issues not presented to or decided by the trial court are not preserved for appellate review.
  • Mayes v. St. Luke's Hosp. of Kan. City, 430 S.W.3d 260 (Mo. banc 2014)
    Cited for the limited and rare use of plain error review in civil cases; the majority used this to decline review of the unpreserved unconscionability/class waiver argument.

6. The dissent’s waiver authorities (and the fault line)

  • Village of Cairo v. Bodine Contracting Co., 685 S.W.2d 253 (Mo. App. 1985) and Boulds v. Dick Dean Econ. Cars, Inc., 300 S.W.3d 614 (Mo. App. 2010)
    In dissent, these cases support a broader view: pursuing judicial resolution of arbitrable issues can be inconsistent with arbitration. The dissent treated GMT’s motion to dismiss “with prejudice” as a deliberate merits bid in court—enough, in its view, to constitute inconsistency under Sundance.
  • Giudicy v. Mercy Hosps. E. Cmtys., 645 S.W.3d 492 (Mo. banc 2022) (quoting Dieser v. St. Anthony's Med. Ctr., 498 S.W.3d 419 (Mo. banc 2016))
    Used by the dissent to argue the “right to arbitrate” does not match the definition of an affirmative defense (because it does not defeat liability; it merely changes the forum).

B) Legal Reasoning

1. The majority’s step-by-step waiver framework

  1. Start with Sundance: waiver is “knowingly acting inconsistently” with arbitration, and courts must apply the usual procedural rules.
  2. Identify the “usual” Missouri rule for waiver: under Lucas Hunt Village Co. v. Klein and O'Connell v. Sch. Dist. of Springfield R-12, implied waiver requires a clear and unequivocal relinquishment—conduct so indicative of waiver that “no other reasonable explanation is possible.”
  3. Classify arbitration as an affirmative defense: relying on Dorris v. State and a line of Missouri appellate and federal cases (including GFS, II, LLC v. Carson, Gentry v. Orkin, LLC, Lopez v. GMT Auto Sales, Inc., and Johnson Assocs. Corp. v. HL Operating Corp.), the majority held the right to arbitrate is an “avoidance” that should be raised in responsive pleadings.
  4. Apply Missouri pleading rules: because GMT moved to compel arbitration before filing its answer and pleaded arbitration as an affirmative defense in a timely answer, its conduct did not “clearly and unequivocally” show an intent to relinquish arbitration.
  5. Downplay the “with prejudice” prayer: invoking Mo. State Conf. of NAACP v. State, Mitchell v. Phillips, and Bell v. Shelter Gen. Insur. Co., the Court treated the Rule 55.27(a)(6) motion as non-merits in nature and, in any event, as consistent with multiple reasonable explanations (e.g., procedural mistake), which prevents a finding of clear implied waiver under Lucas Hunt Village Co. v. Klein.

2. Assignment: contract text controls

On the assignment issue, the Court applied straightforward contract interpretation. Lange argued the bank became “us” after assignment, eliminating GMT’s right to compel arbitration. The Court rejected that reading because the arbitration clause expressly covered disputes between Lange and GMT and also included “successors or assigns.” The assignment language appeared on the same page as the arbitration provision, reinforcing that the parties contemplated assignment without loss of GMT’s arbitration election.

3. Unconscionability/class waiver: preservation governs

Although the arbitration clause included a “poison pill” provision (if the class waiver is found unenforceable, the remainder of the arbitration provision becomes unenforceable), the Court refused to reach the issue because Lange did not present it to the circuit court. Applying Brown v. Brown and the restrictive civil plain-error standard from Mayes v. St. Luke's Hosp. of Kan. City, the Court declined review.

4. The dissent’s competing approach

Judge Ransom’s dissent framed the key act—filing a motion to dismiss “with prejudice” and pressing statutory/MMPA merits arguments—as a decisive election to resolve arbitrable issues in court. Under that view, GMT’s conduct was inconsistent with arbitration regardless of whether the motion to dismiss is technically a merits adjudication tool; the inconsistency lies in the attempt to obtain a final judicial merits disposition before turning to arbitration after losing.

The dissent also contested the majority’s “affirmative defense” characterization, reasoning that arbitration does not defeat liability on the merits but only shifts the forum—making it ill-suited to Rule 55.08’s affirmative-defense concept and thus waivable even before an answer is filed.

C) Impact

1. A concrete Missouri rule on pre-answer litigation and waiver

The opinion’s most significant precedential contribution is its answer to a common procedural sequence: a defendant may file a Rule 55.27(a)(6) motion to dismiss and still preserve arbitration, so long as the defendant promptly moves to compel arbitration and timely pleads arbitration as an affirmative defense. In other words, a motion to dismiss for failure to state a claim is not automatically “inconsistent” with arbitration under Morgan v. Sundance, Inc. as Missouri now applies waiver principles.

2. Elevated importance of “timely invocation” rather than “prejudice”

Although Sundance removed prejudice from the federal waiver analysis, this decision shows Missouri’s emphasis will likely rest on (a) whether arbitration was promptly asserted as an affirmative defense, (b) whether the movant substantially litigated before demanding arbitration (as in Lopez v. GMT Auto Sales, Inc.), and (c) whether the conduct clearly and unequivocally communicates abandonment of arbitration.

3. Litigation strategy effects

  • For defendants: The decision reduces the perceived penalty of filing an early motion to dismiss for failure to state a claim, provided arbitration is asserted quickly and formally in the pleadings. It also incentivizes raising arbitration in the answer and moving to compel early to avoid a “substantial participation” waiver theory.
  • For plaintiffs: Waiver arguments will likely require more than pointing to a single early dispositive motion; plaintiffs may need to show prolonged court litigation or a clearer merits election (e.g., extensive discovery, repeated merits motions, or other conduct making arbitration practically impossible).

4. Doctrinal tension left for future cases

The majority-dissent split signals future disputes over how far this “no waiver” principle extends. Questions likely to recur include: (i) whether other pre-answer filings (e.g., motions aimed more directly at merits resolution) trigger waiver, (ii) whether requesting dismissal “with prejudice” matters when the motion is procedurally non-merits in character, and (iii) whether characterizing arbitration as an “affirmative defense” should control waiver timing in all cases.

4) Complex Concepts Simplified

Waiver (express vs. implied)
An express waiver is a direct statement giving up a right. An implied waiver arises from conduct. Missouri requires implied waiver to be “clear and unequivocal”—conduct that leaves no reasonable explanation other than intentional relinquishment.
“Acting inconsistently” with arbitration (Morgan v. Sundance, Inc.)
A party acts inconsistently with arbitration when it behaves like it chose the court system to resolve the dispute instead of arbitration. The Missouri Supreme Court held that filing a motion to dismiss for failure to state a claim—by itself and followed by a timely arbitration demand—did not meet that threshold here.
Rule 55.27(a)(6) motion to dismiss
This motion tests whether the petition alleges a legally cognizable claim; it is not meant to decide whether the plaintiff ultimately wins on the facts. That distinction mattered because it weakened the inference that GMT made a decisive “merits election” inconsistent with arbitration.
Affirmative defense (Rule 55.08)
An affirmative defense is typically something that defeats liability even if the petition’s allegations are true (e.g., statute of limitations). The majority treated the right to arbitrate similarly because it can bar a lawsuit from proceeding in court. The dissent disagreed, viewing arbitration as merely a forum-selection mechanism rather than a merits-defeating defense.
Preservation and plain error (civil)
Appellate courts usually only review issues that were presented to and decided by the trial court. “Plain error” review in civil cases is rare and reserved for clear, obvious errors that create manifest injustice. Here, the unconscionability/class waiver argument was not preserved, and the Court declined to reach it.
Assignment and “successors or assigns” language
When a contract is assigned, rights may pass to another party. But contract language can preserve certain rights for the original party or extend obligations to assignees. Here, the arbitration clause expressly included “successors or assigns,” so assignment did not eliminate GMT’s ability to compel arbitration.

5) Conclusion

Lange v. GMT Auto Sales, Inc. establishes a clear Missouri rule on arbitration waiver after Morgan v. Sundance, Inc.: a defendant does not necessarily waive arbitration by filing a pre-answer motion to dismiss for failure to state a claim, particularly when the defendant promptly moves to compel arbitration and timely pleads arbitration as an affirmative defense. The decision aligns waiver with Missouri’s general “clear and unequivocal” implied-waiver doctrine and positions arbitration as a defense that must be timely invoked in pleadings.

The opinion’s broader significance lies in its practical guidance: early procedural litigation is not automatically incompatible with arbitration, but delay and substantial participation in court litigation (as illustrated by Lopez v. GMT Auto Sales, Inc.) can still support waiver. The dissent underscores that close cases will remain where a party’s court filings look like an attempted merits end-run around arbitration.