Yes, it is illegal to lie about having an STD in most of the United States, and even where no specific criminal statute applies, the person you infected can sue you for money damages. Roughly 40 states have laws that criminalize knowingly transmitting or exposing a partner to HIV or other sexually transmitted diseases, and civil liability exists in every state regardless of whether prosecutors bring charges. What you actually face depends on the disease, the state you’re in, and whether you actively lied or simply said nothing.
When Lying About an STD Becomes a Crime
Criminal prosecution almost always turns on one word: knowingly. Prosecutors have to prove you had been diagnosed or tested positive before the sexual encounter, and that you either lied about your status or failed to disclose it. Someone who genuinely did not know they were infected generally cannot be convicted, though a civil lawsuit is still possible.
Penalties vary widely. HIV-related offenses are charged as felonies in most states that have a specific statute, with prison exposure ranging from a few years to more than a decade. Other STDs more often carry misdemeanor penalties, though some states treat hepatitis B and hepatitis C the same as HIV and elevate those cases to felonies as well.
About a dozen jurisdictions have no HIV- or STD-specific criminal law at all. In those states, prosecutors reach for general statutes like assault, battery, or reckless endangerment. The practical difference matters: general criminal laws typically require proof that the disease was actually transmitted, while many STD-specific statutes criminalize mere exposure. You can be charged under an exposure law even if your partner never gets infected.
Which Diseases Are Covered
HIV dominates the criminal side, and that is where the overwhelming majority of prosecutions have happened. Several states include hepatitis B and hepatitis C in their exposure statutes, and a few have laws broad enough to cover any communicable disease transmissible through sexual contact. Herpes, despite being incurable and widespread, is generally handled in civil court rather than criminal court, though a handful of broadly worded statutes could reach it in theory.
Getting Sued for Lying About an STD
Criminal charges and civil lawsuits run on separate tracks. Even if prosecutors pass on the case, or your state has no STD-specific crime on the books, the person you infected can take you to civil court. The standard of proof there is lower: not “beyond a reasonable doubt,” just “more likely than not.”
Three legal theories do most of the work in these cases.
- Negligence. You knew or should have known about your infection, you failed to disclose it or take precautions, and your partner contracted the disease. This is the most common basis for an STD lawsuit, and it does not require proof that you deliberately lied.
- Battery. Your partner’s consent to sex was not valid because it rested on incomplete information. The argument is that a reasonable person would not have consented knowing the truth, so the contact was effectively nonconsensual.
- Fraudulent misrepresentation. You actively lied when asked about your STD status. This theory requires proof of a false statement, not just silence.
The silence-versus-lie line matters. Negligence covers both. Fraud requires an affirmative lie. Battery depends on whether consent was meaningfully informed. A plaintiff can pursue more than one theory and let the jury sort out which fits.
What Those Lawsuits Can Cost
Damages fall into three buckets.
- Economic damages. Medical bills for testing, treatment, and ongoing care. Lost wages from time off work. For incurable infections like herpes or HIV, projected lifetime medication and medical costs.
- Non-economic damages. Compensation for pain, emotional distress, anxiety, reputational harm, and the effect on the plaintiff’s ability to form intimate relationships.
- Punitive damages. Extra money meant to punish, awarded when the conduct was especially reckless or malicious. Actively lying when directly asked, or infecting multiple partners, pushes a case toward punitive territory.
Jury awards in STD cases have reached into the millions, particularly in herpes transmission cases where the defendant clearly knew and lied. Herpes is actually the most frequently litigated STD in civil court. It is incurable, common enough that many people carry it, and often spread by partners who know their status and say nothing.
Defenses If You’re Accused
Depending on the facts, several defenses may be available.
- The partner already knew. If the other person was aware of your status and chose to have sex anyway, their consent was informed. This is probably the strongest defense available and can defeat both criminal charges and civil claims.
- Reasonable precautions. Evidence that you used condoms, disclosed your status, or took other protective steps can support a defense, especially in negligence cases where the question is whether you behaved reasonably.
- The plaintiff’s own conduct. If the plaintiff had other sexual partners during the relevant window, the defense can argue someone else was the source. That attacks the causation element every case requires.
- No actual knowledge. In criminal cases especially, if you had not been diagnosed when the encounter happened, you did not “knowingly” expose anyone. You cannot conceal what you don’t know.
In states that have modernized their HIV laws, having an undetectable viral load on antiretroviral therapy may be a complete defense to exposure charges. Michigan’s law, for example, provides that a person adhering to a treatment plan with medically suppressed viral levels is not acting with reckless disregard. Other states, including Florida, explicitly reject undetectable status as a defense, meaning charges can proceed even where the risk of transmission was effectively zero.
How Long Someone Has to Sue You
Civil claims come with a filing deadline. For negligence, the window is typically two to three years. Fraud claims often run longer, roughly two to six years, because the deception itself can delay discovery of the harm.
When the clock starts is the key question. Most states follow the “discovery rule,” which starts the limitations period when the plaintiff learned, or reasonably should have learned, that they were infected, not when the sexual contact happened. That matters because many STDs are asymptomatic for long stretches. Someone who contracts herpes but has no outbreak or positive test for two years generally has the clock start at diagnosis.
The discovery rule cuts both ways. Courts expect people to investigate suspicious symptoms within a reasonable time. Ignoring obvious signs for a year before testing can push the court to start the clock at the point a reasonable person would have sought care.
Why the Same Conduct Isn’t Treated the Same Everywhere
Most STD criminalization laws were written in the late 1980s and early 1990s, when an HIV diagnosis was effectively a death sentence. Medical science has moved on. Antiretroviral therapy can suppress HIV to an undetectable viral load, and people with undetectable viral loads cannot transmit the virus sexually. Many state statutes have not caught up.
Some states are updating. California reduced its HIV exposure offense from a felony to a misdemeanor, and other states have narrowed their statutes to focus on intentional transmission rather than mere exposure, or added a defense for people whose viral load poses no realistic risk. Other states have left the older framework in place.
The result is a patchwork. The same conduct that draws no charges in one state can be a felony in another. Public health groups have broadly criticized the older laws, arguing that criminalizing exposure discourages testing, since a person can only “knowingly” transmit a disease they know they have.
The Role of Consent
Consent is the thread running through both the criminal and civil sides of these cases. For consent to sex to be legally meaningful, it has to be informed. When one partner hides a diagnosis, the other partner’s agreement rests on false information, and many jurisdictions treat that as no real consent.
In a civil battery claim, consent obtained through deception is not valid consent, which turns the physical contact into a harmful or offensive touching. In criminal cases, the absence of informed consent is often what triggers the exposure or transmission statute, since those laws generally apply only when the partner was not told. The law tends to presume that a reasonable person would not consent to the risk of contracting a serious disease, and that presumption is hard to overcome without proof the partner genuinely knew and accepted the risk.