Missouri's legal system imposes strict temporal boundaries on auto accident claims through statutory limitations periods, common law doctrines, and procedural rules that collectively determine when it becomes "too late" to pursue legal action. The primary statute of limitations for personal injury claims under RSMo. § 516.120(4) establishes a five-year window from the date of accident for filing lawsuits, while property damage claims under RSMo. § 516.120(2) also carry a five-year limit. However, this seemingly generous timeframe is complicated by notice requirements for governmental defendants (RSMo. § 537.600), insurance policy notification clauses, and evidentiary preservation deadlines that create de facto earlier cutoffs. The Missouri Supreme Court's interpretation of the "discovery rule" (Sheehan v. Sheehan, 901 S.W.2d 57 (Mo. banc 1995)) further modifies these deadlines for latent injuries, adding layers of complexity to the question of legal timeliness.

II. Missouri's Core Statute of Limitations: RSMo. § 516.120 and Its Exceptions

The foundational five-year statute for personal injury claims under RSMo. § 516.120 applies to most auto accident cases, but exceptions exist:

• Wrongful death claims under RSMo. § 537.100 must be filed within three years of death (not accident date)

• Claims against municipalities require 90-day notice under RSMo. § 537.610 before suit

• UM/UIM claims often have contractual deadlines as short as one year in insurance policies
  The Missouri Court of Appeals in Nolan v. Republic Insurance Co., 155 S.W.3d 850 (Mo. App. 2005) upheld strict enforcement of policy notification periods, creating potential traps for unwary claimants.

III. The Discovery Rule and Delayed Symptom Onset

Missouri recognizes the discovery rule exception when injuries are not immediately apparent, as established in Powderly v. South County Anesthesia Assoc., 245 S.W.3d 267 (Mo. banc 2008). For example:

• Whiplash symptoms may take 72+ hours to manifest

• Traumatic brain injuries (TBI) might show delayed cognitive deficits

• Disc herniations could become symptomatic months post-accident
  The limitations period begins when a "reasonable person would have known" of the injury, per Sheehan, but proving delayed discovery requires neurological expert testimony and contemporaneous medical records.

IV. Minors and Tolling Provisions: RSMo. § 516.170

Missouri law tolls statutes of limitations for minors until they reach majority (age 18), per RSMo. § 516.170:

• A 16-year-old accident victim would have until age 23 to file (5 years after turning 18)

• However, parents filing derivative claims for medical expenses must still comply with the five-year limit
  The Eastern District clarified in Doe v. Roman Catholic Diocese, 347 S.W.3d 588 (Mo. App. 2011) that tolling doesn't apply to parental loss of consortium claims.

V. Governmental Liability: The 90-Day Notice Trap

Claims against Missouri DOT, St. Louis County, or Breckenridge Hills municipal vehicles require:

1. Written notice within 90 days of accident (RSMo. § 537.610)

2. Lawsuit filing within two years (RSMo. § 537.600)
   Failure to comply is jurisdictionally fatal, as held in State ex rel. Missouri Highway & Transportation Commission v. Dierker, 961 S.W.2d 58 (Mo. banc 1998).

VI. Insurance Policy Deadlines: Contractual Shortening of Rights

Missouri allows insurers to impose shorter deadlines than statutory limits:

• GEICO, State Farm, and Progressive policies often require:

  • Notice of claim within 30 days

  • Proof of loss within 1 year

  • UM/UIM claims filed within 2 years
    The Western District enforced such clauses in Rodriguez v. General Accident Ins. Co., 808 S.W.2d 379 (Mo. App. 1991), even where the statute of limitations hadn't expired.

VII. Spoliation Doctrines and Evidentiary Deadlines

Missouri's spoliation doctrine creates practical deadlines earlier than statutory limits:

• Black box data from vehicles is typically overwritten within 30-90 days

• Traffic camera footage in St. Louis County is deleted after 30 days

• Witness memories degrade rapidly after 6-12 months
  The Eastern District's Henderson v. Fields, 68 S.W.3d 455 (Mo. App. 2001) held that failure to preserve evidence could warrant adverse jury instructions.

VIII. Comparative Fault Investigations: RSMo. § 537.765

Missouri's pure comparative fault system means late-filed claims face heightened scrutiny:

• Defendants will allege plaintiff memory lapses

• Insurers argue lost evidence prejudiced their defense

• Juries may assign higher percentage fault to plaintiffs with delayed claims
  The Missouri Approved Jury Instructions (MAI) 37.07 explicitly permit such arguments.

IX. Medical Treatment Gaps and Damage Reduction

Missouri courts reduce awards for failure to mitigate damages (MAI 11.06):

• Gaps in treatment become "apportionment issues"

• Insurers hire IME doctors to allege injuries were unrelated

• Delayed MRIs allow defense arguments about preexisting conditions
  The Southern District's Langley v. Curators of Univ. of Missouri, 73 S.W.3d 808 (Mo. App. 2002) approved 50% damage reductions for treatment delays.

X. Strategic Advantages of Early Legal Retention

Even within statutory limits, late retention harms cases by:

1. Lost witness statements (affidavits stale after 1+ years)

2. Destroyed vehicle evidence (junked cars lose defect evidence)

3. Unpreserved social media (posts deleted showing pre-injury activities)

4. Settlements undervaluing future surgeries

XI. Conclusion: The Functional Deadline Framework

While Missouri's five-year statute provides nominal breathing room, the functional deadlines are far shorter:

• 90 days for government claims

• 1 year for optimal evidence preservation

• 2 years before memory degradation prejudices cases

• 5 years as absolute cutoff with mounting defenses
  Plaintiffs should consult St. Louis County personal injury attorneys immediately to navigate this complex temporal minefield.