A real but minority approach
Most US states use some form of modified comparative negligence — one that bars recovery once a claimant's own fault crosses a 50% or 51% threshold. Pure comparative negligence, the rule Arizona follows for ordinary negligence, takes that threshold away entirely. Thirteen states share this general approach: Alaska, Arizona, California, Florida, Kentucky, Louisiana, Mississippi, Missouri, New Mexico, New York, Rhode Island, South Dakota, and Washington.
A mix of large and small states
This group is a genuinely varied mix — it includes some of the most populous states in the country, like California, New York, and Florida, right alongside Arizona and much smaller states like Rhode Island. Pure comparative negligence isn't tied to any particular region or state size; it's simply the fault-allocation approach each of these states chose to adopt, whether through statute or through their own courts.
Arizona's real point of difference within this group
It's worth being precise here: Arizona's membership in this group comes with a genuine asterisk. Under A.R.S. § 12-2505, the core proportional-reduction principle is the same as its peers — but Arizona's statute directly denies the benefit of comparative negligence to a claimant whose own conduct was intentional, willful, or wanton. For that specific category of conduct, Arizona's rule stops behaving like a pure comparative state and instead reverts to something much closer to old-style contributory negligence. Most of the other twelve states in this group don't carve out this kind of exception in the same explicit statutory form.
The contrast worth understanding
At the opposite end of the spectrum sit the five contributory negligence jurisdictions — Alabama, Maryland, North Carolina, Virginia, and the District of Columbia — where any fault at all on a claimant's part, even ordinary carelessness, can bar recovery completely. Arizona's ordinary rule produces a very different outcome for ordinary negligence, but converges toward that same all-or-nothing territory specifically where the claimant's own conduct was willful or wanton.
Why this matters in a disputed Arizona claim
Because Arizona's ordinary rule has no threshold that can eliminate a claim over routine fault alone, a disputed fault percentage for ordinary negligence changes the size of the recovery, not the entire case. But that changes sharply the moment an insurer argues the claimant's own conduct crossed into willful or wanton territory — at that point, the stakes look far more like the contributory negligence jurisdictions described above. See our full comparison of how Arizona's rule fits among all four fault systems for the complete picture.