Four systems, and Iowa uses the more common middle version
American fault law splits into four real categories: pure comparative negligence, modified comparative negligence with a 50% bar, modified comparative negligence with a 51% bar, and pure contributory negligence. Iowa uses the 51% bar — the more typical of the two modified thresholds nationally.
Iowa's rule: barred only when you exceed them
Under Iowa Code § 668.3, a claimant recovers as long as their fault was not greater than the combined fault of the defendants. A claimant at exactly 50% still recovers half their damages; only crossing to 51% bars recovery entirely.
Iowa adopted this system by statute in 1984
Iowa's modified comparative fault framework isn't ancient — it was enacted through the Comparative Fault Act, codified in Iowa Code chapter 668, in 1984, replacing an earlier judicial approach that had developed through case law. This gives Iowa a relatively clean, statute-driven version of the 51% rule compared to states where the rule evolved more gradually through court decisions alone.
The stricter alternative: a 50% bar
A smaller group of about 12 states, including Georgia and Idaho, use a stricter version: recovery is barred the moment the claimant's fault is equal to the defendant's, not only when it exceeds it. A claimant at exactly 50% recovers nothing in those states, while the same claimant recovers a meaningful amount in Iowa.
Pure comparative negligence and contributory negligence: the two extremes
At the more forgiving end of the spectrum, pure comparative negligence states like California never bar recovery for ordinary fault at all. At the far stricter end, the five contributory negligence jurisdictions — Alabama, Maryland, North Carolina, Virginia, and DC — bar recovery entirely for any fault, even 1%. See our guide to the other states using a 51% bar for Iowa's closest peer group nationally.