CGIA Notice Clock Runs from Discovery of Injury (Not Identification of the Responsible Public Entity) and Requires Strict Compliance Under § 24-10-109(1)

I. Introduction

In Mostellar, Jaimi v. City of Colorado Springs (2026 CO 22), the Colorado Supreme Court addressed a recurring problem in Colorado Governmental Immunity Act (“CGIA”) practice: a claimant is injured on property seemingly controlled by one public entity, timely gives that entity notice, and only later learns that a different public entity may be legally responsible due to an intergovernmental agreement.

The petitioner, Jaimi J. Mostellar, alleged that she was injured on August 26, 2021 when she tripped over the base of a removed bus stop sign on a public sidewalk in Manitou Springs. She timely provided CGIA notice to Manitou Springs. In April 2023, Manitou Springs allegedly informed her—more than a year and a half after the fall—that an intergovernmental agreement made the City of Colorado Springs responsible for the condition connected to her accident. Mostellar then provided notice to Colorado Springs on May 30, 2023.

The key issues were (1) when the CGIA’s 182-day notice period begins under § 24-10-109(1)—upon discovery of the injury or upon learning which public entity is potentially liable—and (2) whether strict compliance should yield when a claimant allegedly could not timely identify the correct public entity because another public entity delayed disclosure.

II. Summary of the Opinion

The Court affirmed dismissal for lack of subject matter jurisdiction. It held:

  • Strict compliance with § 24-10-109(1) is required; the statute is a jurisdictional non-claim provision not subject to equitable doctrines (waiver, tolling, estoppel).
  • The 182-day period begins on the date of discovery of the injury—here, the injury date itself (August 26, 2021)—not when the claimant learns the identity or involvement of the public entity that may be liable.
  • Even if another public entity’s conduct was problematic, it was irrelevant to the claimant’s statutory duty to provide timely notice to the entity “entitled to notice” (Colorado Springs), because Colorado Springs did not itself mislead or hinder compliance.

III. Analysis

A. Precedents Cited

1. Trinity Broad. of Denver, Inc. v. City of Westminster

The Court relied on Trinity Broad. of Denver, Inc. v. City of Westminster, 848 P.2d 916 (Colo. 1993), to restate the modern CGIA trigger: the notice period begins when a claimant “knew or, through the exercise of reasonable diligence, should have known” that they were wrongfully injured—and critically, the claimant “need not yet know the cause of the injury or the extent of the damage.” This precedent anchored the Court’s rejection of a “responsible-entity discovery” trigger.

2. State v. Young and the 1986 Legislative Override

The district court had relied on State v. Young, 665 P.2d 108 (Colo. 1983), for the proposition that a claimant must have a reasonable opportunity to discover “basic and material facts” (including who caused the injury) before notice is required. The Supreme Court held that this reliance was misplaced because the legislature amended § 24-10-109(1) in 1986 to override Young’s approach.

The Court reinforced that point through Reg'l Transp. Dist. v. Lopez, 916 P.2d 1187 (Colo. 1996), which recognized that the 1986 amendment clarified that the notice clock runs upon discovery of the injury, “regardless of whether the person then knew all of the elements of a claim.” In other words, Young’s broader “basic and material facts” discovery concept does not govern § 24-10-109(1) as currently written.

3. Mesa Cnty. Valley Sch. Dist. No. 51 v. Kelsey; City & Cnty. of Denver v. Crandall

The Court relied on Mesa Cnty. Valley Sch. Dist. No. 51 v. Kelsey, 8 P.3d 1200 (Colo. 2000), for two foundational CGIA propositions: (i) noncompliance with § 24-10-109(1) mandates dismissal for lack of subject matter jurisdiction; and (ii) § 24-10-109(1) is a non-claim statute, meaning it is not subject to equitable defenses. The Court cited City & Cnty. of Denver v. Crandall, 161 P.3d 627 (Colo. 2007), in accord.

4. Finnie v. Jefferson County School District R-1 (and the § 24-10-109(1) vs. (3) Divide)

Mostellar argued that equity and agency principles should excuse her late notice because Manitou Springs allegedly withheld information. The Court treated Finnie v. Jefferson County School District R-1, 79 P.3d 1253 (Colo. 2003), as the key counterpoint—but ultimately as inapplicable.

Finnie distinguished between:

  • § 24-10-109(1) (the deadline): a jurisdictional prerequisite requiring strict compliance; and
  • § 24-10-109(3) (the place/manner of filing): a statutory defense permitting substantial compliance analysis considering “principles of agency and equity” and the need to protect plaintiffs from misrepresentations.

The Court emphasized Finnie’s logic: substantial compliance was warranted there because the entity entitled to notice (through its risk management personnel) affirmatively directed the claimant to file notice in a particular way and then tried to capitalize on that misdirection. Here, by contrast, Colorado Springs did nothing to mislead or impede Mostellar; any alleged delay by Manitou Springs could not be imputed to excuse noncompliance with Colorado Springs’ independent entitlement to timely notice under § 24-10-109(1).

5. Jefferson Cnty. Health Servs. Ass'n v. Feeney

To justify reading the statute as written (despite acknowledged harshness), the Court cited Jefferson Cnty. Health Servs. Ass'n v. Feeney, 974 P.2d 1001 (Colo. 1998), describing CGIA notice purposes: prompt investigation and remediation of dangerous conditions, encouraging prompt settlement, fiscal planning for potential liability, and preparation of defenses. The Court treated strict adherence to § 24-10-109(1) as aligned with those legislative objectives.

6. Procedural/interpretive framework cases

The Court cited City of Boulder v. Pub. Serv. Co. of Colo., 2018 CO 59, for de novo review of a C.R.C.P. 12(b)(1) ruling where jurisdictional facts are not disputed, and Pub. Serv. Co. of Colo. v. Outdoor Design Landscaping LLC, 2026 CO 6, for standard interpretive canons (plain language controls unless ambiguous).

B. Legal Reasoning

  1. Text controls. The Court found § 24-10-109(1) unambiguous: notice must be filed within 182 days after “discovery of the injury,” “regardless of whether the person then knew all of the elements of a claim.”
  2. Strict compliance is jurisdictional. Because § 24-10-109(1) is a non-claim statute, failure to comply “forever bar[s]” the action; courts lack subject matter jurisdiction and may not apply equitable doctrines to extend time.
  3. Young does not govern. Any requirement that a claimant discover “who caused it” before the clock starts is inconsistent with the post-1986 statutory scheme recognized in Lopez and applied in Trinity.
  4. Misleading conduct matters only when attributable to the entity entitled to notice (and typically under § 24-10-109(3)). The Court treated Finnie’s equity-focused approach as tied to § 24-10-109(3) and, even if extrapolated, as requiring misleading or obstructive conduct by the defendant entitled to notice—absent here.
  5. Application was straightforward. Mostellar discovered her injury on August 26, 2021. Notice to Colorado Springs in May 2023 was well beyond 182 days; dismissal was mandatory.

C. Impact

The decision clarifies and hardens a practical rule for CGIA litigants: the § 24-10-109(1) clock does not wait for a claimant to identify the correct public entity, even where intergovernmental agreements obscure responsibility and even where another public entity allegedly delays disclosure.

Likely consequences include:

  • Earlier multi-entity notice practice. Claimants and counsel may feel compelled to provide protective CGIA notices to all potentially involved public entities (municipality, county, special district, RTD-related entities, etc.) soon after the injury.
  • Accelerated investigation demands. The burden of quickly identifying ownership/control/maintenance responsibility (including via public records requests) falls heavily on claimants within the 182-day period.
  • Limited role for fairness arguments. Courts are instructed to treat perceived inequity as a legislative matter when § 24-10-109(1) is clear, reinforcing the jurisdictional “bright line.”
  • Legislative pressure. The opinion echoes the special concurrence below urging the General Assembly to consider statutory modifications to address situations where one public entity’s conduct may contribute to noncompliance—though the Supreme Court itself declines to craft a judicial remedy.

IV. Complex Concepts Simplified

  • Non-claim statute: a deadline that extinguishes the right to sue if missed, not merely a defense that can be waived. Under the CGIA, missing the notice deadline generally ends the case.
  • Jurisdictional prerequisite: a requirement that must be satisfied before a court has authority to hear the case. If unmet, dismissal is required.
  • “Discovery of the injury” (CGIA): awareness that you were injured (and that it was wrongful), not knowledge of every legal element, not certainty about the correct defendant, and not full knowledge of causation details.
  • Strict vs. substantial compliance: strict compliance means exact adherence; substantial compliance allows near-enough compliance when the statute’s purposes are met. This opinion emphasizes strict compliance for the § 24-10-109(1) deadline, while Finnie recognized substantial compliance for certain § 24-10-109(3) filing-location disputes.

V. Conclusion

Mostellar reinforces a bright-line CGIA rule: under § 24-10-109(1), the 182-day notice period begins when the claimant discovers the injury, not when the claimant later learns which public entity may be responsible. The Court also limits fairness-based arguments by reaffirming that the notice deadline is jurisdictional and not subject to equitable doctrines, particularly where the defendant entitled to notice did not mislead the claimant. Any remedy for the harshness that can result from hidden intergovernmental responsibility, the Court signals, lies with the legislature rather than judicial modification of the statute’s plain text.