STATE LAW – ARIZONA LIBRARY – GUIDE 17
Comparative Fault
How Arizona reduces damages for a claimant’s own fault, allocates responsibility among defendants and nonparties, and generally makes each defendant responsible only for that defendant’s percentage of fault.
In an ordinary Arizona negligence claim, claimant fault usually reduces recovery rather than eliminating it.
A.R.S. § 12-2505 provides that contributory negligence or assumption of risk is a jury question. If the jury applies
either defense, the claimant’s damages are reduced in proportion to the claimant’s relative fault that proximately
caused the injury or death. Arizona then uses § 12-2506 to allocate fault among defendants and properly considered nonparties.
IMPORTANT LIMIT
The ordinary comparative-fault rule should not be overstated. Section 12-2505 states that a claimant who intentionally,
wilfully, or wantonly caused or contributed to the injury or wrongful death has no right to comparative negligence under that section.
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CLAIMANT FAULT
Section 12-2505 reduces damages according to the claimant’s percentage of fault
Arizona does not use an ordinary 50-percent or 51-percent bar for negligence claims. If the claimant is negligent,
the trier of fact assigns a percentage of fault and the recoverable damages are reduced by that percentage.
Jury question
Section 12-2505 makes contributory negligence and assumption of risk questions of fact for the jury.
Arizona’s constitutional tradition likewise strongly protects the jury’s role in resolving those defenses.
Proximate contribution
The reduction is based on the claimant’s relative degree of fault that proximately caused the injury or death.
Mere criticism of the claimant’s conduct is not enough; the asserted fault must be legally connected to the loss.
SIMPLE FORMULA
Proven damages × (100% − claimant’s percentage of fault) = damages remaining before allocation among defendants,
settlements, liens, policy limits, or other adjustments.
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DEFENDANT ALLOCATION
Arizona generally uses several-only liability
A.R.S. § 12-2506(A) generally provides that each defendant is liable only for the damages allocated in direct proportion
to that defendant’s percentage of fault, subject to the statute’s specific exceptions.
Total damages
The trier of fact first determines the recoverable damages under the applicable law.
Whole allocation
The claimant, defendants, and properly considered nonparties are apportioned together as a whole.
Separate defendant liability
Each defendant ordinarily pays only the share corresponding to that defendant’s percentage of fault.
WHY THIS MATTERS
Identifying every responsible actor can materially change the amount recoverable from a particular defendant.
Fault assigned to an insolvent, immune, absent, or nonparty actor generally is not automatically transferred to another defendant.
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NONPARTIES AT FAULT
Fault can be allocated to someone who is not a defendant
Section 12-2506(B) directs the trier of fact to consider the fault of all persons who contributed to the injury,
death, or property damage, whether or not they were or could have been named as parties, when the statute and court rules
permit the nonparty’s fault to be considered.
Properly designated nonparty
A defendant may identify a person or entity alleged to be wholly or partly at fault. If the procedural requirements
are met and the evidence supports fault, the jury may allocate a percentage to that nonparty.
Settled nonparty
Section 12-2506(B) separately permits consideration of a nonparty’s negligence or fault when the plaintiff entered
into a settlement agreement with that nonparty.
NO JUDGMENT AGAINST THE NONPARTY
Allocation to a nonparty is used to determine the percentages of the named parties. Section 12-2506(B) states that
the assessment does not itself subject the nonparty to liability in that action or another action.
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PROCEDURAL NOTICE
Current Rule 26(b)(5) sets a 150-day notice deadline after the answer
Under the current Arizona Rule of Civil Procedure 26(b)(5), a party alleging that a person not currently or formerly named
as a party was wholly or partly at fault must serve the required nonparty-at-fault notice no later than 150 days after filing
its answer, unless the parties agree or the court permits a later notice under the rule.
The notice must identify the nonparty
The procedural designation is not satisfied by vague suggestions that “someone else” may have caused the crash.
The party must comply with the current rule’s disclosure requirements.
Late designation requires rule-based relief
If the deadline is missed, do not assume the nonparty can still be placed on the verdict form.
Check the rule’s current good-cause, diligence, agreement, and prejudice requirements.
RULE VERSION MATTERS
Older Arizona opinions and secondary sources may quote prior Rule 26(b)(5) deadlines. Use the current rule for the
case’s procedural calendar rather than copying an older 60-day formulation.
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EVIDENTIARY FOUNDATION
A designation does not substitute for proof that the nonparty was actually at fault
McDaniel v. Payson Healthcare
The Arizona Supreme Court reaffirmed that a jury may be instructed on a nonparty’s comparative fault only if the
trial evidence is adequate to support a finding that the nonparty was negligent or otherwise at fault.
Causation remains required
The party seeking the allocation must establish an actionable breach or other legally recognized fault and a causal
connection to the injury or damage. Naming a nonparty alone does not create a percentage of fault.
CRASH APPLICATION
Preserve evidence concerning every potentially responsible driver, vehicle owner, employer, road contractor,
vehicle manufacturer, maintenance provider, public entity, and other actor before the nonparty-designation deadlines expire.
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JOINT-LIABILITY EXCEPTIONS
Several-only liability has statutory exceptions
Section 12-2506(D) identifies circumstances in which one party may be responsible for another person’s fault or share.
For ordinary Arizona crash analysis, two exceptions deserve particular attention.
Acting in concert
Joint responsibility may apply where the defendant and another person were acting in concert within the statutory framework.
Agent or servant
A party may be responsible for the fault of another person acting as that party’s agent or servant.
This can intersect with employer/employee crash liability and respondeat-superior analysis.
THIRD STATUTORY EXCEPTION
Section 12-2506(D) also contains a Federal Employers’ Liability Act exception. Verify the full statutory text whenever
a case falls outside an ordinary motor-vehicle negligence action.
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BROAD CONCEPT OF FAULT
Arizona can compare different forms of legally recognized fault
Hutcherson v. City of Phoenix explains the breadth of Arizona’s comparative-fault system. The Court held that
Arizona’s allocation framework permitted the jury to compare negligent conduct with intentional conduct in the case before it.
The decision emphasizes that Arizona’s statutory definition of fault is broad and that allocation occurs as a whole.
DO NOT MISSTATE THE HOLDING
Hutcherson does not convert intentional conduct into negligence. It addresses whether different forms of legally recognized
fault can be compared for allocation under Arizona’s statutory scheme.
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WORKED EXAMPLE
How the percentages affect recovery
Assume a jury finds total damages of $500,000 and allocates fault as follows:
20%
Claimant
$100,000 reduction attributable to claimant fault.
50%
Defendant A
Ordinarily responsible for $250,000 under several liability.
30%
Nonparty B
$150,000 allocated to the nonparty; the allocation itself does not create a judgment against that nonparty.
SIMPLIFIED EXAMPLE ONLY
Actual judgments can also be affected by settlements, releases, joint-liability exceptions, policy limits,
liens, setoffs, evidentiary rulings, and other substantive or procedural rules.
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PRACTICAL METHOD
Build a fault map before assigning percentages
1
List every actor
Claimant, drivers, owners, employers, contractors, public entities, manufacturers, maintenance providers, and any other person whose conduct may have contributed.
2
Identify the legal duty
For each actor, identify the duty, alleged breach, and conduct that could constitute statutory “fault.”
3
Connect conduct to causation
Record how the conduct allegedly caused or contributed to the injury or property damage.
4
Classify party status
Named defendant, claimant, settled tortfeasor, potential nonparty at fault, agent/servant, immune actor, or unknown actor.
5
Calendar Rule 26(b)(5)
Track the current 150-day post-answer deadline for any required nonparty-at-fault notice.
6
Preserve proof
Collect witness, vehicle, video, EDR, phone, employment, maintenance, roadway, and expert evidence needed to prove actual fault.
7
Check statutory exceptions
Before treating liability as purely several, test § 12-2506(D)’s acting-in-concert, agency/servant, and FELA provisions.
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PRIMARY & OFFICIAL SOURCES
Authorities for this guide
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VERIFICATION
Formal QC for an Arizona comparative-fault conclusion
- Separate claimant fault under § 12-2505 from multi-party allocation under § 12-2506.
- Confirm the alleged claimant conduct proximately contributed to the injury or death.
- Identify every person or entity whose fault may require allocation.
- Determine whether any potential tortfeasor has settled with the claimant.
- Calendar the current Rule 26(b)(5) nonparty-at-fault deadline from the filing of the answer.
- Use the current rule, not an older case quoting a superseded deadline.
- For every nonparty designation, identify evidence sufficient to prove actual fault and causation.
- Check § 12-2506(D) before concluding liability is several only.
- Check agency/servant relationships, particularly in employer-vehicle cases.
- Keep settlements and releases cross-linked to § 12-2504 and CLM-040.
- Verify later Arizona appellate treatment before publishing a new comparative-fault proposition.
QC STATUS
A.R.S. §§ 12-2505, 12-2506, and 12-2504 were checked against the current Arizona Legislature compilation.
Current Rule 26(b)(5) was checked for the 150-day notice period. Hutcherson and McDaniel were checked against
official Arizona Supreme Court opinions on September 26, 2026.
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COMMON QUESTIONS
Questions to ask
If I am partly at fault for an Arizona crash, do I automatically lose the claim?
No. In an ordinary negligence claim, § 12-2505 generally reduces damages in proportion to the claimant’s fault rather than imposing a 50-percent or 51-percent bar.
What if the claimant is 80% at fault?
In an ordinary negligence case subject to § 12-2505, the claimant’s recovery can still be reduced by 80% rather than automatically barred. The statute’s intentional/wilful/wanton limitation must be considered separately where applicable.
Is every defendant jointly liable for the whole judgment?
No. Section 12-2506 generally makes liability several only, with each defendant responsible for that defendant’s proportionate share, subject to the statutory joint-liability exceptions.
Can fault be assigned to someone who was never sued?
Yes, in circumstances allowed by § 12-2506(B) and the Arizona Rules of Civil Procedure. A timely and sufficient nonparty-at-fault designation and evidentiary basis may be required.
How long does a defendant currently have to identify a nonparty at fault?
Current Rule 26(b)(5) generally requires the notice no later than 150 days after filing the answer, subject to agreement or relief allowed by the rule.
Does naming a nonparty automatically put that person on the verdict form?
No. McDaniel confirms that there must be adequate evidence from which the jury could find the nonparty actually at fault.
Can Arizona compare negligent conduct with intentional misconduct?
Hutcherson holds that Arizona’s broad allocation framework allowed comparison of negligent and intentional fault in the case before the Court. The conduct retains its own legal character; it is being compared for allocation purposes.
What if the other driver was working for an employer?
Check § 12-2506(D)’s agent-or-servant exception and the separate Arizona respondeat-superior analysis. Continue to the Work, Employer & Commercial Vehicles topic.
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CONTINUE RESEARCH
Related Arizona topics
VG-CRASH-INVESTIGATION · Crash Investigation & Evidence Preservation
VG-COMMERCIAL-WORK · Work, Employer & Commercial Vehicles
CLM-040 · Settlement, Releases & Finality
RESEARCH MAINTENANCE
Master topic: VG-COMPARATIVE-FAULT · Authority review cycle: 15 days
Primary change triggers: §§ 12-2505 / 12-2506, Rule 26(b)(5), and Arizona Supreme Court decisions addressing fault allocation or nonparty designations.
PRIMARY SOURCES
§§ 12-2505 · 12-2506 · Rule 26(b)(5)
Official-source QC · September 26, 2026
Official Sources
Verify current Arizona law at the source
The detailed authority links above are preserved from the reviewed Arizona guide. Use current official sources before legal reliance.