California Lemon Law 18-Month / 18,000-Mile Presumption: How Song-Beverly §1793.22 Works (2026)

California’s Song-Beverly Act includes a powerful shortcut: if specific conditions are met within 18 months or 18,000 miles of vehicle delivery, the vehicle is presumed to be a lemon. The burden of proof flips to the manufacturer to rebut the presumption — and that’s hard for them to do.

This page breaks down exactly when the 18/18 presumption applies, why “rebuttable” matters, and what your options look like if your timeline falls outside the 18/18 window.

The presumption in plain English

Lemon law presumption applies when 4 repair attempts (or 2 attempts for safety-of-life defects, or 30+ cumulative business days out of service) happen within 18 months OR 18,000 miles — whichever comes first.

That’s the rebuttable presumption codified at California Civil Code §1793.22(b). When it attaches, the vehicle is presumed a lemon, and the manufacturer has to prove otherwise.

The four conditions — all must be met

1. The defect substantially impairs use, value, or safety

Not every defect qualifies. The defect has to materially affect the vehicle’s use, value, or safety to the buyer. Cosmetic blemishes don’t qualify; recurring transmission failure does.

2. The buyer notified the manufacturer

Service-center visits aren’t enough on their own. The buyer (or the buyer’s lawyer) typically must give written notice to the manufacturer at some point during the process. Check your warranty for the specific notification address; for most claims, this happens once a lemon attorney enters the picture.

3. One of three repair triggers

Whichever applies to your facts:

• Standard trigger: 4 or more repair attempts for the same nonconformity
• Safety trigger: 2 or more repair attempts for a defect likely to cause death or serious bodily injury
• Out-of-service trigger: 30 or more cumulative business days out of service for warranty repairs (any defects, not just the lemon one)

The safety trigger and the out-of-service trigger are both lower thresholds than the 4-attempt standard. Many cases that don’t reach 4 attempts still attach the presumption through one of these.

4. All within 18 months OR 18,000 miles

The 4th repair attempt (or 2nd safety attempt, or 30th business day) must occur before the earlier of:

• 18 months from vehicle delivery, OR
• 18,000 miles on the odometer

This is a “whichever first” calculus, not “either / or”. A daily commuter putting on 15,000 miles a year hits the 18,000-mile limit first, around month 14. A garage queen putting on 3,000 miles a year hits the 18-month limit first, well before 18,000 miles.

Why “rebuttable” matters

The presumption isn’t a final judgment — it shifts the burden of proof. Once the conditions are met, the manufacturer must prove the vehicle is NOT a lemon, typically by trying to show:

• The defect was caused by buyer abuse or unauthorized modification
• The defect doesn’t actually substantially impair use / value / safety
• The repair attempts weren’t really for the same nonconformity (the recategorization tactic — see below)

In practice, manufacturers struggle to rebut a properly documented 4-attempt presumption. The presumption is the consumer’s leverage — it changes the negotiation posture from “you have to prove your case” to “the manufacturer has to break out of the presumption.”

What “substantially impairs” actually means

The three-prong test:

• Use — can the vehicle be driven as intended? A transmission that lurches, an engine that stalls in traffic, an infotainment system that doesn’t work, brakes that pulse — all qualify.
• Value — has the defect materially affected what the vehicle is worth? Recurring electrical issues, persistent paint defects, structural concerns often qualify even if the vehicle still drives.
• Safety — does the defect create risk of injury? Brakes, airbags, steering, seat belts, fuel system issues clearly qualify, often with the lower 2-attempt safety trigger.

A defect only needs to substantially impair one of the three to count. Most genuine lemons impair multiple categories.

What if you’re outside the 18/18 window?

You can still have a lemon law claim. The presumption is a shortcut, not a requirement.

Outside 18/18:

• The repair-attempt standard becomes “reasonable opportunity to repair” — fact-specific, but courts have applied it to vehicles with 25,000-50,000+ miles and 2-3+ years of service.
• You’d typically have to prove the manufacturer had a reasonable opportunity to fix the issue. Documentation matters more without the presumption’s automatic burden flip.
• A civil penalty can still apply if the manufacturer’s conduct was willful — and the buyback formula works the same way regardless of whether the presumption attached.

Many successful lemon law cases involve vehicles past 18/18. The 18/18 presumption is the easy path; the harder path still exists.

What dealers and manufacturers don’t tell you

Service departments won’t tell you about the presumption. They’re trained to fix cars, not advise you on §1793.22(b) mechanics. Multiple visits for the same issue rarely come with a “this is starting to look like a presumption” warning. The clock runs whether you know about it or not.

They sometimes manipulate the attempt count. If a service advisor codes your transmission complaint as different “issues” across visits — “rough shifting” vs “delayed engagement” vs “shudder under load” — the manufacturer may argue these aren’t the same nonconformity, breaking the 4-attempt count. Push back; insist that the underlying issue is the same.

The “out of service” trigger is broader than people realize. It’s 30 cumulative business days for warranty repairs of any kind — not specific to one defect. If your car has been in the shop multiple times for different issues totaling 30+ days, the presumption can attach on that basis alone.

The “safety” trigger only needs 2 attempts. Manufacturers don’t volunteer this. If your defect involves brakes, airbags, steering, seat belts, or anything else likely to cause death or serious bodily injury, the bar is much lower than the standard 4 attempts.

When to talk to a Lemon Law attorney

The 18/18 presumption is documentable from your repair orders alone. If you’ve had 4+ repair attempts for the same issue, or 2+ for a safety defect, or 30+ cumulative days out of service — and you’re inside the 18/18 window — you likely meet the presumption. A free case review will tell you whether your specific paperwork triggers it.

If you’re approaching the 18/18 cutoff, time matters: you want a claim filed (or a written demand sent) before the window closes. If you’re already past 18/18, that doesn’t end the case. It just changes which legal standard applies. A free review will tell you what your facts support either way.