Rule 55.27(a)(6) Motion to Dismiss Does Not Waive Arbitration When Arbitration Is Timely Invoked and Pleaded as an Affirmative Defense

Case: Connie Lange v. GMT Auto Sales, Inc. (No. SC100608)  |  Court: Supreme Court of Missouri (en banc)  |  Date: March 18, 2025

1. Introduction

This appeal arises from a consumer transaction in which Connie Lange purchased a fifth-wheel camping trailer from GMT Auto Sales and was charged a $199 “administrative fee” purportedly authorized by section 301.558, RSMo 2016. Lange filed a putative class action alleging the fee violated the Missouri Merchandising Practices Act (“MMPA”) because fifth-wheel camping trailers allegedly are not among the items (a “motor vehicle,” “vessel,” or “vessel trailer”) for which section 301.558 permits such a fee.

The sale involved a retail installment contract containing an arbitration provision. After first filing a motion to dismiss for failure to state a claim under Rule 55.27(a)(6), GMT moved (six days after the motion to dismiss was denied) to compel arbitration and also pleaded arbitration as an affirmative defense in its timely answer. The circuit court compelled arbitration; the arbitrator awarded Lange $199 plus $5,000 in attorney fees and costs. Lange then sought to vacate the award and to revisit the arbitration-compulsion order; the circuit court confirmed the award. The court of appeals reversed on waiver grounds, and the Supreme Court of Missouri granted transfer.

The Supreme Court addressed three issues: (I) whether GMT retained a contractual right to invoke arbitration after assignment of the installment contract; (II) whether GMT waived arbitration by first filing a Rule 55.27(a)(6) motion to dismiss; and (III) whether an unconscionability challenge based on a class-waiver-related clause was preserved.

2. Summary of the Opinion

The Court affirmed confirmation of the arbitration award. It held:

  • No waiver: GMT did not waive the right to arbitrate by filing a motion to dismiss for failure to state a claim before moving to compel arbitration, where GMT moved to compel arbitration before filing its responsive pleading and pleaded arbitration as an affirmative defense.
  • Assignment did not eliminate GMT’s arbitration right: The arbitration clause’s text covered disputes between Lange and GMT “or our employees, agent, successors or assigns,” and the contract’s definitions and structure contemplated assignment without forfeiting GMT’s right to elect arbitration.
  • Unconscionability argument unpreserved: Lange’s argument that the arbitration provision became unenforceable if the class waiver was unenforceable was not raised in the circuit court and was not reviewed (no request for plain error review; no manifest injustice shown).

Judge Ransom dissented, reasoning GMT acted inconsistently with arbitration under Morgan v. Sundance, Inc. by seeking a merits disposition “with prejudice” in court before turning to arbitration, and further disputing the majority’s characterization of the right to arbitrate as an affirmative defense insulated from waiver until omitted from an answer.

3. Analysis

A. Precedents Cited

1) Federal arbitration framework and anti-discrimination principle

  • Morgan v. Sundance, Inc., 596 U.S. 411 (2022): The majority treated Sundance as requiring arbitration motions to be handled under “the usual procedural rules,” rejecting special, arbitration-tilting waiver rules and focusing on whether a party “knowingly act[ed] inconsistently” with arbitration. This case supplied the controlling waiver standard and the caution against bespoke arbitration-favoring (or disfavoring) doctrine.
  • AT&T Mobility LLC v. Concepcion, 563 U.S. 333 (2011): Cited for FAA preemption principles—state doctrines may not be applied “in a fashion that disfavors arbitration.” The majority used Concepcion to justify importing Missouri’s ordinary waiver doctrine rather than crafting an arbitration-specific waiver test.

2) Missouri law on waiver and implied waiver

  • Lucas Hunt Village Co. v. Klein, 218 S.W.2d 595 (Mo. banc 1949): The majority used this decision’s “clear and unequivocal” implied-waiver standard—conduct must be “so manifestly consistent” with waiver “that no other reasonable explanation is possible.” This was central to rejecting waiver based solely on a motion to dismiss.
  • O'Connell v. Sch. Dist. of Springfield R-12, 830 S.W.2d 410 (Mo. banc 1992): Reinforced the need for conduct that “clearly and unequivocally show[s] a purpose to relinquish the right” for implied waiver.

3) Motion-to-dismiss jurisprudence (not a merits determination)

  • Mo. State Conf. of NAACP v. State, 601 S.W.3d 241 (Mo. banc 2020) and Mitchell v. Phillips, 596 S.W.3d 120 (Mo. banc 2020): Used to characterize a Rule 55.27(a)(6) motion as a test of petition adequacy, not merits.
  • Bell v. Shelter Gen. Insur. Co., 701 S.W.3d 614 (Mo. banc 2024): Cited for the proposition that even legal questions may be prematurely decided on a motion to dismiss; the “only inquiry” is whether a cognizable claim is stated.
  • Mahoney v. Doerhoff Surgical Servs., Inc., 807 S.W.2d 503 (Mo. banc 1991): Noted to support the majority’s point that dismissal with prejudice is generally not the “greatest relief” available on a first failure-to-state-a-claim dismissal without prior opportunity to plead further.
  • City of St. Louis v. State, 682 S.W.3d 387 (Mo. banc 2024) and Emerson Elec. Co. v. Marsh & McLennan Co., 362 S.W.3d 7 (Mo. banc 2012): Contrasted with motions to dismiss by noting that judgment on the pleadings is a merits resolution.

4) Arbitration as an “affirmative defense” and litigation conduct

  • GFS, II, LLC v. Carson, 684 S.W.3d 170 (Mo. App. 2023), Gentry v. Orkin, LLC, 490 S.W.3d 784 (Mo. App. 2016), and Lopez v. GMT Auto Sales, Inc., 656 S.W.3d 315 (Mo. App. 2022): The majority relied on these to support that arbitration should be asserted in responsive pleadings and that waiver can occur through substantial participation in litigation, especially delays and extensive motion practice.
  • Johnson Assocs. Corp. v. HL Operating Corp., 680 F.3d 713 (6th Cir. 2012): Quoted for the idea that an enforceable right to compel arbitration can operate as a “quasi-jurisdictional bar” and for the view that failure to raise arbitration as an affirmative defense indicates intent to litigate.
  • Messina v. N. Cent. Distributing, Inc., 821 F.3d 1047 (8th Cir. 2016): Cited as additional federal authority supporting the need to timely assert arbitration.
  • Dorris v. State, 360 S.W.3d 260 (Mo. banc 2012): Provided Missouri’s definition of an affirmative defense, which the majority applied to treat arbitration as a defense that, even accepting petition allegations, bars court adjudication.

5) Preservation and plain error limits in civil cases

  • Brown v. Brown, 423 S.W.3d 784 (Mo. banc 2014): Quoted for the rule that issues not presented to or decided by the trial court are not preserved.
  • Mayes v. St. Luke's Hosp. of Kan. City, 430 S.W.3d 260 (Mo. banc 2014): Used to emphasize that civil plain error review is rare and requires “evident, obvious and clear” error plus manifest injustice.

6) FAA/MUAA relationship and standard of review

  • Car Credit, Inc. v. Pitts, 643 S.W.3d 366 (Mo. banc 2022): Cited for de novo review of motions to compel arbitration and agreement validity/enforceability.
  • Eaton v. CMH Homes, Inc., 461 S.W.3d 426 (Mo. banc 2015): Cited regarding the Missouri Uniform Arbitration Act (“MUAA”) applying where not preempted and being substantially similar to the FAA.

7) Dissent’s waiver authorities and affirmative-defense definition

  • 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): Relied on by the dissent to frame “inconsistency” as submitting arbitrable issues to a court for decision.
  • Giudicy v. Mercy Hosps. E. Cmtys., 645 S.W.3d 492 (Mo. banc 2022) and Dieser v. St. Anthony's Med. Ctr., 498 S.W.3d 419 (Mo. banc 2016): Used by the dissent to argue a motion to compel arbitration is not an “affirmative defense” because it does not defeat liability, but merely redirects the forum.

B. Legal Reasoning

1) The new waiver rule in Missouri arbitration practice (post-Sundance)

The majority’s core doctrinal move is to harmonize Sundance with Missouri’s general waiver principles: if the FAA requires courts to apply “the usual procedural rules,” then Missouri’s ordinary implied-waiver test governs whether litigation conduct amounts to waiver of arbitration. Under Lucas Hunt Village Co. v. Klein and O'Connell v. Sch. Dist. of Springfield R-12, implied waiver requires conduct that “clearly and unequivocally” manifests relinquishment, with no other reasonable explanation.

Applying that test, the Court held GMT’s sequence did not clearly and unequivocally demonstrate abandonment of arbitration because:

  • GMT moved to compel arbitration before filing its responsive pleading.
  • GMT pleaded arbitration as an affirmative defense in a timely answer (a step the Court treated as the procedural marker for preserving defenses under Rule 55.08).
  • A Rule 55.27(a)(6) motion to dismiss tests pleading sufficiency, not merits; therefore, filing it was not inherently “manifestly consistent” with intending to forgo arbitration.

The majority also emphasized an interpretive constraint: because arbitration cannot be singled out for special treatment, a waiver analysis cannot effectively punish a defendant for employing ordinary, generally available procedural motions unless that conduct meets the ordinary, stringent implied-waiver standard.

2) Arbitration as an affirmative defense (and the responsive-pleading anchor)

The Court characterized “the right to arbitrate” as an affirmative defense under Rule 55.08, leaning on Dorris v. State and the line of cases treating failure to plead arbitration as evidence of intent to litigate. On that view, a party “does not waive an affirmative defense until after and unless” it is omitted from the responsive pleading (subject to Rule 55.27(g)’s list of earlier-waived defenses, which does not include arbitration).

This framing functionally makes the timely answer (and inclusion of arbitration therein) a central “safe harbor” against waiver, at least where pre-answer conduct is limited and the motion to compel is made promptly.

3) Assignment: textualism over assumed divestiture

On assignment, the Court treated the contract language as dispositive. The arbitration clause required arbitration of disputes between Lange and GMT “or our employees, agent, successors or assigns,” and the contract defined “Us” to include the seller-creditor (GMT) or its assigns (including the bank). Because the clause was drafted to contemplate assignment on the same page, the Court rejected the argument that assignment extinguished GMT’s ability to elect arbitration.

4) Unconscionability: preservation, not merits

Lange’s attack focused on a clause stating that if the class-action waiver is held unenforceable “the remainder of this Arbitration Provision shall be unenforceable.” The Court did not decide whether that structure is unconscionable or otherwise invalid under Missouri law; it held only that Lange failed to raise the issue in the circuit court. Under Brown v. Brown, the issue was unpreserved, and the Court declined plain-error review under Rule 84.13(c), citing Mayes v. St. Luke's Hosp. of Kan. City.

C. Impact

1) Practical litigation sequencing: “motion to dismiss first” is not automatic waiver

The most significant operational impact is that, in Missouri, filing a Rule 55.27(a)(6) motion to dismiss—standing alone—will not necessarily waive arbitration, particularly where the defendant promptly moves to compel arbitration and pleads arbitration in the responsive pleading. This may encourage defendants to test pleadings early without forfeiting arbitration, so long as arbitration is invoked quickly and formally preserved.

2) The responsive pleading becomes a key waiver checkpoint

By treating arbitration as an affirmative defense whose waiver is tied to omission from the answer (rather than pre-answer conduct), the opinion may narrow waiver arguments in cases where the defendant’s pre-answer litigation conduct is modest and procedural.

3) Drafting and assignment: sellers can preserve arbitration rights post-assignment

On contract drafting, the Court’s assignment analysis signals that sellers/creditors can retain arbitration election rights despite assignment if the clause expressly includes “successors or assigns” and defines the covered parties accordingly.

4) Class waiver “poison pill” clauses: preservation will control many appellate outcomes

The Court’s refusal to reach unconscionability underscores that parties challenging arbitration clauses—especially clauses that attempt to disable arbitration if class waivers fail—must raise those theories early in the circuit court. Otherwise, even potentially significant enforceability questions may be lost on appeal.

5) Continued doctrinal tension (majority vs. dissent)

The dissent’s approach would treat a merits-seeking motion to dismiss “with prejudice” as inconsistent with arbitration regardless of whether the motion is technically a merits adjudication tool. That disagreement foreshadows future litigation over what kinds of pre-answer motions (and requested relief) cross the line into “inconsistent” conduct under Sundance.

4. Complex Concepts Simplified

  • FAA (Federal Arbitration Act): A federal statute favoring enforcement of arbitration agreements and preventing states from applying rules that discriminate against arbitration.
  • Waiver (implied waiver): Losing a contractual right by conduct. Under Missouri law cited here, implied waiver requires conduct so clear that no other reasonable explanation exists.
  • Rule 55.27(a)(6) motion to dismiss: A request to dismiss because the petition’s allegations, even if true, do not state a legally cognizable claim. Missouri precedent in the opinion treats this as a pleading-sufficiency test, not a merits determination.
  • Affirmative defense (Rule 55.08): A defense that must be stated in the answer; it asserts a legal reason the plaintiff cannot obtain relief even if the petition’s factual allegations are accepted. The majority treated the right to arbitrate as fitting this category.
  • Assignment: Transfer of contract rights to a third party (here, to a bank). Whether the original party keeps any rights depends on contract text; the Court enforced the clause’s inclusion of disputes involving “successors or assigns.”
  • Preservation / plain error (Rule 84.13(c)): Appellate courts generally review only issues raised in the trial court. “Plain error” review in civil cases is rare and requires obvious error plus manifest injustice.

5. Conclusion

Connie Lange v. GMT Auto Sales, Inc. establishes (or, at minimum, clarifies) a consequential Missouri rule for arbitration practice after Morgan v. Sundance, Inc.: filing a Rule 55.27(a)(6) motion to dismiss for failure to state a claim does not, by itself, constitute a “clear and unequivocal” waiver of arbitration when the defendant promptly moves to compel arbitration and pleads arbitration as an affirmative defense in its timely responsive pleading. The decision also reinforces textual enforcement of arbitration clauses that preserve rights through assignment and underscores strict preservation requirements for unconscionability and class-waiver-related challenges.