Yes, you can sue someone for giving you an STD in California. The California Supreme Court confirmed in John B. v. Superior Court that a civil cause of action exists for the negligent transmission of a sexually transmitted disease, and liability reaches anyone who knew or had reason to know they were infected. You generally have two years to file, measured from when you discovered (or reasonably should have discovered) the infection and its likely source. What your case is worth, and whether it’s winnable, turns on what the other person knew, what they said, and what you can prove about where the infection came from.
What Kind of Lawsuit You’re Actually Bringing
There is no single “STD lawsuit” in California. You build the case from established tort theories, and more than one often applies to the same facts.
Negligence
This is the usual starting point. The argument is that the other person owed you a duty to take reasonable steps to avoid infecting you, breached that duty, caused your infection, and caused you harm. California’s model jury instruction for negligent sexual transmission of disease (CACI No. 429) lays out these elements.1Justia. CACI No. 429 – Negligent Sexual Transmission of Disease The duty attaches when the person knew or had reason to know they were infected. You don’t need to show a formal diagnosis. Symptoms a reasonable person would have investigated can be enough.
Battery
Battery is harmful or offensive contact without valid consent. You may have agreed to sex, but California courts have recognized that consent given without important information about serious health risks can be invalid. If the other person hid their infection, the theory is that your consent wasn’t informed and the contact was legally nonconsensual. Framing the conduct as intentional rather than careless also opens the door to stronger remedies.
Fraud
If the other person actively lied, saying they were tested and clean, saying they were monogamous, or saying they didn’t have the disease, you may have a fraud claim. The Supreme Court in John B. allowed fraud as a cause of action where the defendant allegedly represented himself as monogamous and disease-free and pressured a shift away from condoms.1Justia. CACI No. 429 – Negligent Sexual Transmission of Disease Fraud requires more than silence. You need an affirmative false statement, intent that you rely on it, and actual reliance to your detriment.
Emotional Distress
Intentional infliction of emotional distress reaches extreme and outrageous behavior. Negligent infliction covers emotional harm tied to the physical injury of being infected. Both were recognized as viable claims in John B., and in many cases the emotional damages end up larger than the medical bills.
What You Have to Prove
Whichever theory you lead with, the core showings overlap:
- The defendant was infected at the time of the sexual contact.
- The defendant knew about the infection, or had symptoms or other information that should have prompted testing. Constructive knowledge counts.1Justia. CACI No. 429 – Negligent Sexual Transmission of Disease
- The defendant did not disclose the infection and did not take reasonable precautions.
- The contact with the defendant is what gave you the STD.
- You suffered actual harm, whether medical costs, emotional distress, or both.
Causation is usually the hardest piece. STDs have incubation periods that run from days to years, so if you had other partners during the relevant window, expect the defense to point at them. The cleaner your timeline, the stronger your case.
How Long You Have to File
California’s personal injury statute of limitations is two years, and it covers assault, battery, and injuries caused by another person’s wrongful act or neglect.2California Legislative Information. California Code of Civil Procedure 335.1 All the theories above fall within that deadline.
When the clock starts is the harder question. Many STDs stay asymptomatic for long stretches, so California’s delayed discovery rule matters. The two years don’t begin until you actually discovered the harm, or until a reasonable person in your position would have suspected it was caused by someone else’s wrongdoing.3Justia. CACI No. 455 – Statute of Limitations – Delayed Discovery You don’t have to know every legal detail. Once you have enough to suspect you were infected through someone else’s carelessness or deception, the countdown runs.
Practically, if you test positive and know you had only one unprotected partner during the relevant window, the positive test likely starts the clock. Don’t wait on confirming the other person’s diagnosis before filing.
Using the Criminal Statute to Strengthen Your Civil Case
California Health and Safety Code Section 120290 makes it a misdemeanor to willfully expose another person to an infectious or communicable disease. A person violates the current statute if they knew they were infected, engaged in conduct posing a substantial risk of transmission, and actually transmitted the disease to someone who did not know about the infection.4California Legislative Information. California Health and Safety Code 120290
Even without a criminal prosecution, the statute helps you in civil court. Under California Evidence Code Section 669, violating a statute creates a rebuttable presumption of negligence.5California Legislative Information. California Evidence Code 669 If you can show the defendant’s behavior fit Section 120290, the court presumes negligence and shifts the burden to the defendant to rebut it. The statutory violation itself becomes evidence.
What the Defense Will Argue
You Were Partly at Fault
California uses pure comparative negligence. If the defendant can show you were careless too, for not asking about STD status, not pushing for protection, or not getting yourself tested when you had risk factors, a jury can assign you a percentage of fault and reduce your damages by that percentage. Even at 60% fault, you still recover 40%.
They Didn’t Know
The simplest defense is that the person genuinely didn’t know and had no reason to suspect. No symptoms, no prior positive test, no warnings from past partners. If that holds up, the knowledge element gets harder to prove.
You Knew and Agreed Anyway
If you knew about the infection and had sex anyway, the defense will raise assumption of risk. California splits this into primary assumption of risk, which can bar your claim entirely, and secondary assumption of risk, which folds into comparative negligence and only reduces damages. Knowing and proceeding anyway can land in the primary category and sink the case.
Someone Else Gave It to You
If you had other sexual partners during the incubation window, expect the defense to argue one of them was the source. Medical evidence about incubation periods and testing timelines becomes central.
What You Can Recover
Economic damages cover measurable losses: testing, treatment, ongoing care, prescriptions, therapy, and lost wages. For chronic or incurable infections like herpes or HIV, future medical costs can be substantial and are recoverable.
Non-economic damages cover the harm that doesn’t come with a receipt. Pain and suffering, emotional distress, anxiety about future health, strain on intimate relationships, and loss of enjoyment of life. In STD cases these often exceed the medical bills, because the stigma, disclosure anxiety, and relationship fallout last longer than any physical symptoms.
Punitive damages are available when the conduct amounts to oppression, fraud, or malice. California Civil Code Section 3294 requires clear and convincing evidence of one of those three.6California Legislative Information. California Civil Code 3294 Malice means the defendant intended to injure you or acted with willful and conscious disregard for your safety. Someone who knows they have an active, transmissible STD, lies about it, and refuses to use protection fits that description.
Tax Treatment
Most of what you recover is tax-free federally. Under Internal Revenue Code Section 104(a)(2), damages received on account of personal physical injuries or physical sickness are excluded from gross income, and lost wages tied to that claim come along for the ride.7Internal Revenue Service. Tax Implications of Settlements and Judgments An STD infection is a physical injury, so compensatory damages generally qualify, including emotional distress damages that arise from the infection itself.
Punitive damages are taxable as ordinary income.7Internal Revenue Service. Tax Implications of Settlements and Judgments If a settlement doesn’t allocate the payment among damage types, the IRS may treat the whole amount as taxable. Structuring the settlement matters, and it’s worth running past a tax professional before signing.
Whether You Can Actually Collect
Winning and collecting are different problems. Most personal injury judgments are paid by insurance, but STD cases don’t fit that pattern well. Homeowners and renters liability policies typically exclude intentional acts, so if the defendant deliberately concealed the infection, their insurer will almost certainly deny coverage. Even on a negligence theory, many liability policies now carry broad communicable disease exclusions that bar coverage for bodily injury from disease transmission regardless of fault.
That usually means collection depends on the defendant’s personal assets. California allows wage garnishment and property liens, which help if the defendant has income or property to reach. If they don’t, a judgment can be hard to enforce even after you win. This is worth working through with an attorney before you file.
What Happens to Your Private Medical Information
Both sides’ health records come into play in these cases, and the privacy concern keeps some people from filing. HIPAA restricts disclosure of health information, but federal law carves out exceptions for judicial proceedings. A covered healthcare provider can release records in response to a court order, or to a subpoena that meets specific notice requirements.8U.S. Department of Health & Human Services. Judicial and Administrative Proceedings Your attorney obtains the defendant’s relevant records through normal discovery.
Courts routinely issue protective orders in cases involving sensitive medical information, restricting who can see the records and barring public disclosure. Discovery materials that aren’t filed with the court generally stay private, and judges can tailor protections, including “attorney eyes only” designations for the most sensitive material. Courts handle medical records in injury cases every day, and the tools to protect both sides’ dignity already exist.