Ascertainability Is Not a Mandatory Prerequisite Under Montana Rule 23: Predominance and Early-Stage Deference Affirmed in Allied Waste v. LH Residential

Introduction

In Allied Waste v. LH Residential (2025 MT 203), the Montana Supreme Court affirmed an order certifying two Rule 23(b)(3) classes in a dispute over “three-yard” commercial dumpsters that, according to plaintiffs, were materially undersized. The case arises from allegations that Republic Services of Montana (Allied Waste Services of North America, LLC d/b/a Republic Services of Montana) provided containers labeled and billed as three cubic yards when many actually held less—often around 2.52 cubic yards for a common model (Capital #443). Plaintiffs LH Residential LLC and Otis Street LLC, both doing business as Montana Crestview (collectively, Crestview), alleged breach of contract and negligent misrepresentation and sought to represent all similarly situated Republic customers in Missoula County.

On appeal from the Fourth Judicial District Court’s certification order, Republic raised two challenges:

Predominance: Whether common issues of law and fact predominate over individualized questions under M. R. Civ. P. 23(b)(3).
Ascertainability: Whether the district court erred by certifying the classes without separately determining the “ascertainability” of class membership.

The Court’s opinion clarifies key aspects of Montana class action law: it reaffirms that individualized damages do not ordinarily defeat predominance where liability questions are common; it underscores substantial deference to early certification decisions; and, most notably, it rejects a stand-alone “ascertainability” prerequisite under Montana Rule 23, while recognizing that trial courts may consider class member identification issues within existing Rule 23 frameworks and case-management powers.

Summary of the Opinion

The Supreme Court affirmed certification of two Rule 23(b)(3) classes covering customers who paid for “three-yard” dumpster service but were provided dumpsters “measuring 2.6 cubic yards or less,” for claims of breach of contract (from October 19, 2014) and negligent misrepresentation (from October 19, 2019).
Predominance was satisfied because the core question—whether Republic breached agreements or made tortious misrepresentations by providing undersized “three-yard” dumpsters—is common to the class and will move the litigation forward efficiently, even though damages may vary across class members.
The Court distinguished cases involving individualized liability determinations and reiterated Montana’s approach that individualized damages typically do not defeat predominance in contract-based class actions.
There is no free-standing ascertainability requirement under Montana Rule 23. Trial courts may consider how class members can be identified as part of predominance, superiority, and case-management analyses, but they are not required to make a separate ascertainability finding before certifying a class.
Given early-stage factual disputes and limited discovery, appellate courts will not “micromanage” certification; district courts retain flexibility to refine or modify class definitions under M. R. Civ. P. 23(c)(1)(C) as the evidentiary record develops.

Analysis

Factual posture and class definitions

Crestview obtained Republic’s services under an original signed agreement and subsequently on an invoice-by-invoice basis after the original agreement expired. The service framework required customers to select dumpster size and frequency of pickup; “three-yard” service was a standard option. In a 2021 Public Service Commission hearing, Crestview learned that Republic’s commonly used Capital #443 “three-yard” container actually measured about 2.52 cubic yards. Republic rotated these containers across customers and did not track which customer had which model when. Crestview alleged (1) breach of contract through provision of undersized containers and (2) breach through charging “overage” fees when undersized containers appeared “overfull.”

In light of information revealed during certification briefing, Crestview refined the class definitions to customers who paid for “three-yard” service but were provided dumpsters measuring 2.6 cubic yards or less during the relevant periods. The district court bifurcated discovery (certification first, merits second), recognized some overlap with merits for certification, and certified the two (b)(3) classes on predominance and superiority grounds.

Precedents cited and their influence

Kramer v. Fergus Farm Mut. Ins. Co., 2020 MT 258: The Court relied on Kramer for several points: the abuse-of-discretion standard; the requirement that Rule 23 elements be proven “in fact”; and, critically, the principle that individualized damages questions “typically do not negate class certification as to contractual liability.” Kramer also endorses class treatment where resolving common issues will materially advance the litigation and promote judicial economy, echoing the core purpose of Rule 23(b)(3).
Knudsen v. Univ. of Mont., 2019 MT 175: Cited for basic Rule 23 principles and, along with Kramer, for the notion that individualized damages do not generally defeat class certification when liability turns on common terms and practices.
Mattson v. Mont. Power Co., 2012 MT 318: Quoted for the predominance inquiry’s focus on cohesiveness and judicial economy, stressing that class treatment is favored where it avoids duplicative proceedings and yields uniform answers to common questions.
Diaz v. State, 2013 MT 219: Central to the Court’s deference to early-stage certification decisions: when facts are disputed and discovery is incomplete, appellate courts are “particularly reluctant” to intervene. Diaz also recognizes the district court’s flexibility to modify class definitions under Rule 23(c)(1)(C) and notes that ascertainability may be considered but is not mandated as a standalone requirement.
Sangwin v. State, 2013 MT 373: Republic relied on Sangwin to argue that ascertainability is required and that individualized issues defeat predominance. The Court clarified Sangwin’s actual holding: class certification failed there because resolving liability required individualized determinations on each plaintiff’s denied medical benefit (e.g., whether a procedure was “for research”), not because of any free-standing ascertainability prerequisite. Here, by contrast, liability turns on common conduct and representations about dumpster size.
Jacobsen v. Allstate Ins. Co., 2013 MT 244; Chipman v. Nw. Healthcare Corp., 2012 MT 242: These cases anchor the standards of review: factual findings are reviewed for clear error, legal conclusions de novo, and discretionary certification decisions are overturned only if the trial court acted arbitrarily or exceeded the bounds of reason.
Fink v. Williams, 2012 MT 304: Emphasized the broad discretion trial courts possess in managing and tailoring class proceedings, including addressing administrative or manageability concerns under Rule 23(b)(3) and Rule 23(d).
Comcast Corp. v. Behrend, 569 U.S. 27 (2013): Cited for the requirement that Rule 23 elements be supported by evidentiary proof. The Montana Supreme Court reconciles this with Diaz by allowing early certification on a developing record and authorizing later refinement under Rule 23(c)(1)(C).
Lara v. First Nat’l Ins. Co. of Am., 25 F.4th 1134 (9th Cir. 2022): Distinguished. The Ninth Circuit’s reasoning about individualized damages potentially defeating class certification does not control in Montana, where Kramer and Knudsen confirm that individualized damages “typically” do not bar certification when liability questions are common.

Legal reasoning: Why predominance and why no mandatory ascertainability

Predominance. The Supreme Court agreed with the district court that at least one core question is common to every class member: Did Republic breach contractual and/or tort duties by providing dumpsters substantially smaller than three cubic yards while selling “three-yard” service? That issue encompasses common sub-questions about contractual obligations, uniform or semi-uniform practices, and written and oral representations. Even though Crestview advances two breach theories—(1) the undersized containers themselves and (2) the assessment of overage fees tied to those undersized containers—the first is plainly common, and the second may be addressed through subclassing or refinement if needed. The Court underscored that early certification allows the case to proceed efficiently on these shared issues, and that the district court retains flexibility to narrow or reframe the class (for example, to customers who also paid overage fees) if the merits evidence so requires.

Individualized damages. Relying on Kramer and Knudsen, the Court reiterated that individualized damages do not typically defeat predominance in contract-based class actions. The central objective of Rule 23(b)(3) is judicial economy: resolving disputed contract obligations and alleged uniform misrepresentations one time for all similarly-situated customers is preferable to hundreds or thousands of mini-trials. By contrast, Sangwin involved individualized liability determinations, which is materially different and explains why certification failed there.

No stand-alone ascertainability requirement. Republic argued that the district court was obliged to ensure class membership is “presently and readily ascertainable by objective criteria” before certifying, pointing to Sangwin. The Court rejected that reading. Montana’s Rule 23 already supplies tools to safeguard efficiency and fairness: predominance and superiority (Rule 23(b)(3)), commonality (Rule 23(a)(2)), and robust case-management powers (Rule 23(d)), coupled with the ongoing authority to amend certification orders (Rule 23(c)(1)(C)). While a trial court may consider the ease of identifying class members as part of those analyses, Montana has never recognized a free-standing ascertainability prerequisite—and the Court declined to create one here.

Early-stage deference and flexibility. Echoing Diaz, the Court emphasized reluctance to interfere with class certification at the outset, when facts are disputed and discovery is incomplete. The district court had bifurcated discovery and intentionally limited phase-one efforts to issues necessary for Rule 23, recognizing some merits overlap. That was within its discretion. As the record develops, the court may tailor the class definitions to match the evidence, including with subclasses if certain claims (such as overage-fee claims) require tighter alignment between the theory of liability and the class definition.

Impact and implications

Clarified standard: Montana now expressly confirms that there is no mandatory “ascertainability” element apart from the existing requirements of Rule 23(a) and (b) and the court’s case-management powers. Litigants should frame class-member identification issues within predominance, superiority, manageability, and Rule 23(d) tools—not as a threshold bar.
Early certification is viable despite informational gaps: Plaintiffs need evidentiary support “in fact,” but district courts may certify on an incomplete record when common liability issues are apparent. Defendants’ lack of business records (e.g., no tracking of container models by customer and date) will not, by itself, foreclose certification at the outset.
Individualized damages remain manageable: Contract and misrepresentation cases often involve individualized loss calculations. Under Kramer and Knudsen, that does not usually defeat predominance if liability turns on common conduct, representations, and standardized terms.
Structured class definitions with objective criteria help: Here, the classes were tied to an objective measurement (dumpsters “2.6 cubic yards or less”) within defined time periods and geography. Even though ascertainability is not a mandatory prerequisite, objective criteria enhance administrability and will likely remain best practice.
Expect dynamic class management: The Court signaled openness to subclassing or narrowing (e.g., a separate subclass for overage-fee claims) should the merits record show material differences. Counsel should anticipate tailored discovery and potential refinement of class contours under Rule 23(c)(1)(C).
Broader reach in regulated service contexts: Where services are standardized and marketed by size or capacity, this opinion facilitates class treatment when uniform mislabeling or underspecification is alleged, even if customer-specific usage and damages vary widely.

Complex Concepts Simplified

Predominance vs. commonality: Commonality asks whether there is at least one common question. Predominance asks whether those common questions are more important than the individualized ones, such that trying the case as a class makes sense and saves judicial resources.
Superiority: A class action is “superior” if it’s a better, fairer, and more efficient method than many individual cases to resolve the dispute. It considers factors like judicial economy, consistency of results, and practical manageability.
Ascertainability: Some courts outside Montana require proof that class members can be easily identified at certification. Montana does not impose this as a separate prerequisite. Instead, how class members will be identified is one of many manageability considerations within predominance, superiority, Rule 23(d), and the court’s ongoing supervisory powers.
Abuse of discretion (appellate review): The Supreme Court will not second-guess the trial court’s reasonable choices about class certification. Reversal occurs only if the district court acted arbitrarily or beyond the bounds of reason.
Liability vs. damages: Liability asks whether the defendant violated a duty or a contract. Damages ask how much each plaintiff lost. Montana permits class certification even if the damages for each class member have to be calculated later on an individual basis, so long as liability is driven by common questions.
Rule 23(c)(1)(C) flexibility: Certification is not frozen. Courts can refine or modify class definitions as evidence develops, including creating subclasses or narrowing class scope to match the liability theory.
Bifurcated discovery: Courts may split discovery into phases—first focusing on whether class certification is appropriate, then turning to merits and damages. This controls costs and keeps the case focused on threshold questions.

Conclusion

Allied Waste v. LH Residential squarely confirms two central pillars of Montana class action law. First, predominance is met where common liability questions—here, whether “three-yard” service was delivered through undersized dumpsters and whether related representations were misleading—will efficiently advance the litigation, even if damages vary across class members. Second, Montana does not impose a separate ascertainability prerequisite. Instead, trial courts should use the existing Rule 23 framework—predominance, superiority, and case-management powers—to ensure that certified classes are fair and manageable, and they retain continuing authority to refine classes as the record matures.

For practitioners, the opinion underscores the importance of:

Crafting class definitions with objective, case-linked criteria;
Focusing certification on common liability questions that will drive resolution;
Anticipating later refinement or subclassing where different liability theories (e.g., overage-fee claims) may require tighter fit; and
Using phased discovery and Rule 23(d) tools to streamline proceedings.

In affirming certification, the Court not only provides practical guidance for managing complex, standardized-service disputes but also clarifies that perceived administrative hurdles to identifying every class member at the outset do not categorically bar class treatment in Montana. The decision thus promotes judicial economy and access to justice where common practices can be adjudicated once for all similarly situated customers.