Comparative Negligence in Arizona: Suing When You’re Partly at Fault

“It was partly my fault, so I probably don’t have a case.” People talk themselves out of legitimate claims with that sentence every single day — and in Arizona, it’s almost always wrong. Comparative negligence in Arizona means fault isn’t an on/off switch; it’s a dial. Being partly responsible doesn’t erase your claim. It reduces it, by your percentage, and nothing more. Here’s how the system actually works, who decides the percentages, and how insurers try to turn the dial against you.

Can I sue if I was partially at fault in Arizona?

Yes. Arizona follows what’s called pure comparative negligence (codified at A.R.S. § 12-2505): an injured person’s recovery is reduced in proportion to their own share of the fault — and that’s the entire penalty. Found 20% at fault? You can recover 80% of your damages. 50%? You recover 50%. Under the pure version of the rule, even a person found 90% at fault can still recover the remaining 10% from the other responsible party.

Whether pursuing a small share is practical is a case-by-case judgment. But the legal door stays open at every percentage — and that fact alone should stop anyone from abandoning a claim based on their own guess about blame.

How the math works

The mechanics are refreshingly simple. A jury (or, far more often, negotiating adjusters and lawyers anticipating what a jury would do) answers two questions:

1. What are the total damages? Medical expenses, lost income, property damage, pain and suffering, and the rest — everything the injury cost, valued as if fault weren’t an issue.
2. How does fault divide, in percentages, among everyone involved — including the injured person?

The recovery is then the total damages minus the injured person’s percentage. Someone assessed 30% of the fault recovers 70% of their damages. That’s it. No thresholds, no cliffs, no forfeiture.

Why “pure” matters: Arizona vs. everywhere else

Most states use a harsher variant called modified comparative negligence, where crossing a threshold — typically 50% or 51% fault — bars recovery completely. In those states, a plaintiff found 51% responsible collects nothing at all.

Arizona rejected the cliff. Here, there is no percentage at which your claim evaporates; the reduction is always proportional. A handful of neighboring rules are worth knowing alongside it:

• The one true exception: a person who intentionally caused or substantially contributed to their own injury cannot recover. Comparative fault forgives carelessness by degrees; it doesn’t forgive intent.
• Several liability: under A.R.S. § 12-2506, Arizona defendants generally pay only their own percentage of the damages. If two defendants are 60% and 40% at fault, each owes their share — you usually can’t collect the whole amount from whichever one has deeper pockets. This makes identifying every responsible party matter more here than in many states.
• Juries assign the numbers, when it gets that far: fault percentages are a question of fact, decided case by case on the evidence.

Who actually decides your percentage

Here’s the part the statute doesn’t tell you: in the vast majority of claims, no jury ever assigns a number. The percentage is negotiated — proposed by an insurance adjuster, contested with evidence, and settled somewhere the parties can live with, each side handicapping what a Maricopa County jury would likely do with the facts.

That has a practical consequence worth underlining: your fault percentage is an argument, not a measurement. It moves with the quality of the evidence — photos, witness statements, the police report, camera footage, vehicle damage patterns. The claimant who documented the scene thoroughly negotiates a very different percentage than the one relying on memory. (This is one more payoff of the evidence steps in our post-crash checklist, and it applies just as forcefully to premises cases — where “you should have watched where you were walking” is the standard defense — as we cover in our slip and fall guide.)

How insurers use comparative fault — and how to respond

Because every percentage point assigned to you is a point they don’t pay, comparative fault is the adjuster’s favorite lever. The common moves:

• The early fault question. “Would you say you were maybe going a little fast?” An agreeable answer on a recorded line becomes a fault percentage later. You’re not required to speculate, and you shouldn’t — fault allocation is a conclusion drawn from evidence, not from politeness.
• The unilateral percentage. A letter announces you were “40% at fault” as if it were a finding. It isn’t. It’s an opening position in a negotiation, and it’s contestable with evidence like any other position.
• The both-ways argument. Insurers sometimes assign the injured person a share of fault and undervalue the total damages. Watch both numbers; the payout depends on the multiplication of the two.

The response to all three is the same: don’t accept, don’t argue on the phone, and answer with documentation.

Common Arizona scenarios where fault gets split

A few situations where comparative negligence in Arizona does its everyday work:

• The rear-end crash with a twist. Rear drivers are usually presumed at fault — but a sudden, unexplained stop or dead brake lights on the lead car can shift a percentage forward.
• The pedestrian outside a crosswalk. Jaywalking doesn’t end a claim; drivers still owe care to pedestrians they can see. It typically becomes a percentage argument, not a bar. (Our pedestrian accident guide covers the full rules.)
• The rider without a helmet. Arizona doesn’t require helmets for adult motorcyclists, and helmet use goes to injury severity, not crash causation — a distinction with real consequences we unpack in our guide to the Arizona motorcycle helmet law.
• The left-turn dispute. Turning drivers usually carry the presumption, but excessive speed or a run red light by the oncoming car divides the numbers.

The pattern across all four: the messy, embarrassing fact you think destroys your case usually just prices it. That’s the whole philosophy of the rule.

Deadlines still apply — fully

One thing shared fault does not change: the clock. A claim reduced by comparative fault is still subject to the same filing deadlines as any other — generally two years, with the exceptions and short-fuse traps laid out in our statute of limitations guide. Partial fault reduces the recovery; a missed deadline eliminates it.

The bottom line

Comparative negligence in Arizona replaces “whose fault was it?” with “how does the fault divide?” — and lets injured people recover their share of the damages at any percentage of responsibility, reduced proportionally and no further. The percentage itself is negotiated, evidence-driven, and contested, which means it rewards documentation and punishes phone-call speculation. So if you’ve been telling yourself you have no case because part of it was on you: in Arizona’s at-fault system, that’s not how the math works. Partly at fault is still mostly a claim.

Keep reading: What the helmet law does to motorcycle claims · What if the at-fault driver has no insurance? · or browse all guides from Awesome Attorneys.

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This article is general information about Arizona law, not legal advice, and reading it does not create an attorney–client relationship. Fault allocation is intensely fact-specific and the percentages used above are illustrative only — get case-specific advice from a licensed Arizona attorney before making decisions. If you may be injured, seek medical care first.