Colorado uses modified comparative negligence: below 50% can recover; 50% cannot

C.R.S. § 13-21-111 does not use California-style pure comparative fault. Colorado preserves recovery only when the injured person's negligence is less than the negligence against which recovery is sought.

0% No plaintiff comparative-negligence reduction.

25% Claim is not barred; qualifying damages are reduced for plaintiff fault.

49% Still below the statutory bar.

50% Recovery is barred under the comparative-negligence rule.

Current CJI 9:26 states the rule plainly: if plaintiff and defendant were both negligent and plaintiff's negligence was equal to or greater than defendant's, plaintiff does not recover; if defendant's negligence was greater, recovery continues and the court reduces damages by plaintiff's percentage.

Do not negotiate from the phrase “partly at fault.” In Colorado, the difference between 49% and 50% is not cosmetic. It can be the difference between a reduced judgment and no negligence recovery.

With multiple responsible actors, Colorado combines their fault for the threshold comparison

The injured person's percentage is compared with the combined fault of defendants and properly considered nonparties — not necessarily one defendant at a time.

Colorado combined comparative negligence examples.
Allocation	50% threshold	Result
Plaintiff 40% · Defendant A 60%	40% < 60%	Plaintiff is not barred; damages are subject to the 40% plaintiff-fault reduction.
Plaintiff 50% · Defendant A 50%	50% is equal	Plaintiff is barred.
Plaintiff 40% · Defendant A 30% · Defendant B 20% · Nonparty 10%	40% < combined 60%	Plaintiff is not barred even though plaintiff's 40% exceeds each individual actor's percentage.
Plaintiff 55% · Defendant A 25% · Defendant B 20%	55% ≥ combined 45%	Plaintiff is barred.

Mountain Mobile Mix / Inland-Riggle / B.G.'s: Colorado uses the combined-comparison approach. The plaintiff can clear the threshold even where no single defendant has a percentage greater than the plaintiff's.

Clearing the 50% threshold does not mean one defendant pays the entire remaining loss. Colorado's pro rata liability statute answers that second question.

Threshold is one question; each defendant's payment share is another

C.R.S. § 13-21-111.5 generally limits an independently liable defendant to the degree or percentage of fault attributable to that defendant.

Plaintiff share

Reduces recovery

Plaintiff comparative negligence reduces the recoverable damages under § 13-21-111 and can bar the negligence claim at 50% or more.

Defendant share

Generally several

Each independently liable defendant generally pays no more than the percentage attributable to that defendant.

Nonparty share

Can reduce collectible judgment

A properly allocated nonparty percentage is not automatically shifted onto the remaining defendant simply because that defendant has insurance.

Blakeland Drive Investors v. Taghavi, 2023 COA 30M: an indivisible injury does not itself permit the court to bypass § 13-21-111.5 and impose ordinary joint-and-several liability.

Important exceptions and overlays remain. Section 111.5(4) recognizes joint liability for a conscious conspiracy/common plan to commit a tortious act, while the statute separately preserves respondeat superior, vicarious liability and nondelegable duties. Guide 14 covers employer vehicle responsibility.

The “empty chair” is created by statute — and it has rules

Colorado permits fault to be allocated to a person or entity that is not formally a defendant, but the nonparty must be brought into the comparative framework correctly.

Step 1 Identify nonparty

Name/address or best possible identification.

Step 2 Timely notice

Generally within 90 days after action begins.

Step 3 State legal basis

Why the nonparty owed and breached a duty.

Step 4 Prove causation

How that legal fault contributed to claimed harm.

Step 5 Verdict allocation

Only if admissible evidence supports the percentage.

Torres v. Barnhart, No. 23CA2052 (Colo. App. July 3, 2025): this unpublished C.A.R. 35(e) opinion is a useful current illustration of the statute's timely-designation and factual-basis requirements. It is not binding published Colorado precedent.

Redden v. SCI: saying another actor “caused” the injury is not enough. The designation must support a prima facie basis for legal fault, including the duty and breach that would make that nonparty legally responsible.

A designation creates the issue; evidence earns the percentage

A defendant cannot reduce liability merely by placing another person's name on a verdict form. Colorado requires evidence from which legal fault and causal contribution can be found.

Known driver

Second vehicle

Lane movement, right of way, speed, lookout, braking, signal and impact evidence can support or defeat allocation.

Unknown driver

Phantom vehicle

Colorado can permit best-possible identification of an unknown nonparty, but the defendant still needs evidence rather than speculation.

Immune actor

Not collectible does not always mean irrelevant

An immune nonparty can sometimes receive fault where that person owed the plaintiff a legally recognized duty.

Barton v. Adams Rental: fault may be apportioned to a designated nonparty only when admissible evidence supports the nonparty's contribution to the plaintiff's injury.

“Someone else caused it” and “someone else is at fault” are different defenses. A defendant may deny causation without a valid nonparty designation, but that does not authorize a percentage allocation to the undesignated person.

Settlement does not make a tortfeasor disappear from the allocation map

Colorado expressly permits the fault of a nonparty with whom the claimant has settled to be considered in the final allocation.

Colorado comparative fault and settlement issues.
Event	Comparative-fault consequence
One tortfeasor settles before trial	That person's fault can remain part of the allocation under § 13-21-111.5.
Jury assigns fault to settling nonparty	Colorado settlement-credit statutes and Smith v. Zufelt govern the reduction associated with that allocated percentage.
Settlement release names other persons/entities	Release language can alter the available defendant/coverage map and should be reviewed before execution.
Nonparty has no insurance / cannot pay	The remaining defendant does not automatically absorb that nonparty's share under ordinary pro rata liability.

Fault allocation and settlement credits are separate calculations. Do not assume that every settlement produces a dollar-for-dollar offset or that settling early eliminates the settling actor's percentage from the case.

Seat-belt nonuse is a damages-mitigation issue — not crash-causing comparative negligence

Colorado created a specific statutory seat-belt defense. It should not be folded into the ordinary § 13-21-111 crash-fault percentage.

Colorado seat belt mitigation rules.
Damage category	Seat-belt mitigation under § 42-4-237(7)
Economic loss	Not reduced by the statutory seat-belt mitigation provision.
Medical payments / medical losses	Not reduced by the statutory seat-belt mitigation provision.
Noneconomic pain-and-suffering category	Can be mitigated where the statutory defense is supported.
Inconvenience / emotional stress / quality-of-life impairment	Pringle treats these as within the statute's broad “pain and suffering” category.
Physical impairment / disfigurement	Pringle treats these as a separate category not subject to § 42-4-237(7) mitigation.

Anderson v. Watson: the seat-belt issue is an affirmative defense. The defendant must produce competent evidence of qualifying nonuse, but Colorado does not invariably require expert medical testimony tying each injury to nonuse before the statutory instruction can be given.

Do not let a seat-belt argument inflate the plaintiff's crash-fault percentage. Colorado's statute places qualifying nonuse in the damages-mitigation analysis, with express categories the defense cannot reduce.

Common crash labels still have to survive an evidence test

Rear end

Not automatically 100/0

Following distance matters, but lane changes, unexpected entry, lighting, visibility, braking, speed and other facts can remain disputed.

Left turn

Right of way is important, not the entire reconstruction

Signal phase, oncoming speed, sight distance, lane position and evasive opportunities can affect fault and causation.

Intersection

Signal evidence matters

Traffic-camera footage, signal timing, witnesses, vehicle damage and EDR can be more reliable than later recollection.

Pedestrian / bicycle

Comparative fault can apply

Right of way, visibility and roadway conduct must be analyzed for each actor; vulnerable-road-user status does not eliminate ordinary causation analysis.

Passenger

Driver negligence is not automatically imputed

Any passenger comparative-negligence defense needs the passenger's own negligent conduct and causal contribution.

Citation

Not the final civil verdict

Preserve the citation and report, but test the complete admissible record before turning a traffic enforcement decision into a settlement percentage.

VictimsGuide evidence principle: fault percentages should be tested against the scene, photographs, vehicle movement, witnesses, report, video and missing proof. An adjuster's percentage is a claim position, not a substitute for the evidentiary record.

Separate crash fault from injury causation and post-crash mitigation

Several defenses can reduce a case, but they do not all belong in the same comparative-fault percentage.

Colorado distinction among comparative negligence, seat belt mitigation, causation and damage mitigation.
Issue	Question	Legal role
Comparative negligence	Did claimant's unreasonable pre-injury conduct cause the crash/injury?	§ 13-21-111 percentage; can trigger 50% bar.
Seat-belt nonuse	Did claimant violate the safety-belt statute?	Special § 42-4-237(7) mitigation of specified noneconomic damages.
Medical / injury causation	Did the crash actually cause the claimed condition?	Element of damages/causation; not automatically comparative negligence.
Failure to mitigate after injury	Did claimant unreasonably fail to avoid additional loss after the crash?	Separate mitigation affirmative defense affecting avoidable damages.

Do not allow four different defenses to become one “plaintiff fault” number. The legal category controls the instruction, burden, evidence and effect on damages.

Comparative-fault evidence workflow

Write the movement of each vehicle/person before impact.
Identify every applicable traffic control and right-of-way rule.
Preserve scene and vehicle photographs before repair or destruction.
Preserve surveillance, traffic-camera, dashcam and body-camera footage.
Download EDR, telematics, GPS and fleet/app data when warranted.
Preserve phone records and distraction evidence when legally obtainable.
Identify each witness and preserve contact information promptly.
Compare witness accounts to physical evidence rather than counting witnesses.
Obtain the complete crash report, diagram, supplemental reports and citations.
Document speed, sight distance, weather, lighting, roadway geometry and obstructions.
Identify vehicle defects, tire/brake/lighting issues and maintenance evidence where relevant.
Identify every driver, owner, employer, contractor or public entity potentially at fault.
Identify any unknown/phantom vehicle supported by actual evidence.
Track every nonparty-at-fault designation in litigation.
Test whether the designated nonparty owed the claimant a legal duty.
Test whether admissible evidence supports breach and causal contribution.
Preserve settlement agreements with tortfeasors who may remain in the allocation.
Keep seat-belt evidence separate from crash-causing fault.
Keep post-crash mitigation evidence separate from comparative negligence.
Before settlement, write the competing percentage theories and evidence supporting each.
Reconcile liability percentages with every available liability and UM/UIM policy.

Working rule: do not negotiate against an unsupported percentage. Ask: “What conduct is alleged? What duty did it violate? What evidence proves it? How did it cause this crash or injury? What evidence contradicts it?”

Colorado comparative-fault authority map

Mountain Mobile Mix v. Gifford · 660 P.2d 883 (Colo. 1983)

Combined comparison / 50% rule

Colorado Supreme Court adopted the combined-comparison rule for multiple tortfeasors: plaintiff's negligence is compared with their combined negligence.

Colorado Supreme Court · foundational

Inland/Riggle Oil v. Painter · 925 P.2d 1083 (Colo. 1996)

Designated nonparty included in threshold

Applies combined comparison to designated nonparty fault and illustrates that an immune employer can participate in the allocation framework.

Colorado Supreme Court

B.G.'s, Inc. v. Gross · 23 P.3d 691 (Colo. 2001)

Combined defendants + nonparties

Reaffirms that plaintiff may recover when plaintiff's fault is less than the combined fault of the relevant defendants and designated nonparties.

Colorado Supreme Court

Barton v. Adams Rental · 938 P.2d 532 (Colo. 1997)

Evidence required for nonparty fault

A nonparty percentage must rest on admissible evidence that the nonparty contributed to plaintiff's injury.

Colorado Supreme Court

Redden v. SCI · 38 P.3d 75 (Colo. 2002)

Legal fault — not causation alone

A valid nonparty designation must allege a basis for legal liability, not merely that the nonparty's acts may have caused the injury.

Colorado Supreme Court

Torres v. Barnhart · No. 23CA2052 (Colo. App. July 3, 2025)

Current nonparty-designation illustration

Applies the statutory timely-identification and factual-basis requirements in a rear-end collision involving an unknown SUV, while expressly noting that the opinion is unpublished under C.A.R. 35(e).

Unpublished · C.A.R. 35(e) · illustration only

Blakeland Drive v. Taghavi · 2023 COA 30M

Several liability despite indivisible injury

Section 13-21-111.5's pro rata allocation controls; indivisibility alone does not restore ordinary joint-and-several liability.

Published Colorado Court of Appeals

Anderson v. Watson · 953 P.2d 1284 (Colo. 1998)

Seat-belt mitigation proof

Treats statutory seat-belt mitigation as an affirmative defense and addresses the evidence required to submit the issue to the jury.

Colorado Supreme Court

Pringle v. Valdez · 171 P.3d 624 (Colo. 2007)

What seat-belt mitigation can reduce

Includes broad noneconomic pain-and-suffering losses but excludes physical impairment and disfigurement from § 42-4-237(7) mitigation.

Colorado Supreme Court

Smith v. Zufelt · 880 P.2d 1178 (Colo. 1994)

Settling nonparty fault

Explains the relationship between fault attributed to settling nonparties and reduction of the verdict under Colorado's contribution/settlement framework.

Colorado Supreme Court

Primary authority and current instruction map

C.R.S. § 13-21-111 Comparative negligence / 50% bar

Core Colorado modified comparative-negligence statute and special-verdict framework.

Official 2026 CRS →

C.R.S. § 13-21-111.5 Pro rata liability / nonparty fault

Several liability, designated nonparties, 90-day notice, special verdict and joint-liability exception.

Official 2026 CRS →

C.R.S. § 13-50.5-105 Release / settling tortfeasor consequences

Colorado contribution statute governing specified effects of releases/covenants and percentage allocation.

Official 2026 CRS →

C.R.S. § 42-4-237(7) Seat-belt mitigation

Special statutory mitigation rule limited to pain-and-suffering damages and excluding economic loss/medical payments.

Official 2026 CRS →

2026 CJI · Chapter 9 Negligence and comparative fault

Current pattern instructions 9:22–9:29 for plaintiff comparative negligence, multiple defendants and designated nonparties.

Official 2026 CJI Chapter 9 →

2026 CJI · Chapter 5 Seat-belt and mitigation instructions

Current Colorado pattern instruction notes for § 42-4-237(7), Anderson and Pringle.

Colorado Pattern Civil Jury Instructions →

VictimsGuide resources supporting Guide 17

Guide 18 — Crash Investigation Build the scene, movement, witness, video, EDR and physical evidence needed to test fault. Crash Scene Checklist Preserve evidence before a later fault allocation depends on memory alone. Guide 14 — Work & Commercial Vehicles Identify employers, owners, contractors and other actors who may carry independent fault. Guide 16 — Government Vehicles Public entity immunity and notice issues can coexist with comparative allocation. Guide 04 — UM/UIM Underlying comparative fault can affect the damages the insured is legally entitled to recover. Clean Claim System Organize liability proof before accepting insurer fault percentages or signing a release.

Frequently asked questions

What happens if I am 20% at fault for a Colorado crash?

If comparative negligence is proved and you remain below Colorado's 50% bar, your damages are reduced in proportion to your own percentage, subject to the separate allocation of fault among defendants and nonparties.

Can I recover if I am 49% at fault?

Yes, potentially. Forty-nine percent is below the statutory bar. The damages are then reduced and allocated under the comparative-negligence and pro rata-liability statutes.

Can I recover if I am exactly 50% at fault?

No under the ordinary § 13-21-111 negligence comparison. Colorado requires the plaintiff's negligence to be less than the negligence against which recovery is sought.

If there are two defendants, is my fault compared with each one separately?

No. Colorado uses a combined-comparison approach for the recovery threshold, including properly considered designated nonparties. Payment allocation among the individual defendants is a separate pro rata question.

Can a defendant blame someone who is not being sued?

Potentially. Section 13-21-111.5 permits nonparty fault, but the defending party ordinarily must make a timely statutory designation identifying the nonparty and stating the basis for legal fault, followed by admissible evidence supporting allocation.

How quickly must a defendant designate a nonparty at fault?

Generally within 90 days after commencement of the action, unless the court determines that a longer period is necessary.

Can an unknown driver get a fault percentage?

Potentially. Colorado permits best-possible identification of a nonparty, and current jury-instruction authority recognizes unidentified persons, but evidence still must support legal fault and causation.

Does not wearing a seat belt make me comparatively negligent for causing the crash?

No. Colorado treats qualifying seat-belt nonuse through the separate mitigation rule in § 42-4-237(7). It is not ordinary crash-causing comparative negligence.

Can seat-belt nonuse reduce my medical bills or lost wages?

Section 42-4-237(7) says no. Its mitigation is limited to the statutory pain- and-suffering category and cannot be used to limit economic loss or medical payments.

Is the insurance adjuster's fault percentage legally binding?

No. It is a claim position. A litigated percentage must ultimately be supported by the applicable duties, admissible evidence and causation. Before settlement, test the percentage against the actual crash record.

Comparative-fault worksheet

Worksheet for analyzing Colorado comparative fault in a motor vehicle crash.
Field	Record	Decision question
Plaintiff conduct alleged	__________	What specific conduct is claimed negligent?
Plaintiff duty/breach evidence	__________	What admissible evidence supports the accusation?
Plaintiff causation	__________	How did that conduct cause the crash/injury?
Defendant A fault	__________%	What duty, breach and causation evidence?
Defendant B fault	__________%	What duty, breach and causation evidence?
Designated nonparty	__________	Name/address or best possible identification?
Designation date	__________	Within 90 days or court-authorized extension?
Nonparty legal duty	__________	Did nonparty owe plaintiff a legally recognized duty?
Nonparty proof	__________	Admissible breach and causal evidence?
Settling tortfeasor	__________	Can fault still appear in allocation?
Combined tortfeasor fault	__________%	Is plaintiff below the 50% bar?
Several liability shares	__________	What percentage belongs to each defendant?
Vicarious relationship	__________	Employer/agent/nondelegable-duty overlay?
Seat-belt issue	Yes / No	Separate statutory mitigation rather than crash fault?
Economic damages	$__________	Keep seat-belt mitigation out of this category.
Noneconomic damages	$__________	What portion is within § 42-4-237(7)?
Impairment/disfigurement	$__________	Separate Pringle category.
Post-injury mitigation	__________	Separate from comparative negligence.
Liability policies	__________	Which policy corresponds to each responsible actor?
UM/UIM policies	__________	How does the underlying fault allocation affect legal entitlement?

Closing principle: a comparative-fault percentage is a legal conclusion built from conduct, duty, causation and evidence. Build the record first. Assign the number second.

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