Roughly one in eight people living with HIV in the United States does not know it. For most of them, the barrier is not access. Free tests can be mailed to any American address in discreet packaging, and a self-test takes about 20 minutes at a kitchen table.
CDC's most recent estimate put 1.2 million people in the country living with HIV, with 87 percent aware of their status. That leaves roughly 156,000 people undiagnosed, a figure that has moved only slightly in recent years.
The gap sits inside a better global picture. Worldwide, 88 percent of people living with HIV knew their status in 2025, according to UNAIDS, approaching the 95 percent target for 2030. Reaching it would require an additional 2.9 million people globally to learn their status.
Testing Gap Behind the Numbers
The consequence of late diagnosis is measurable. Among 38,434 people aged 13 and older diagnosed in the United States in 2024, 21.7 percent received a stage 3 classification, meaning advanced disease at the moment of diagnosis, which CDC describes as reflecting "missed opportunities for earlier testing." Only 7.8 percent were caught at stage 0, the earliest detectable point.
Who gets diagnosed late is instructive. The highest rate of stage 3 diagnoses was among people 65 and older, at 35.5 percent, followed by people whose HIV was attributed to heterosexual contact, at 25.1 percent. Those are groups that often do not consider themselves at risk, which is precisely why the federal recommendation is written broadly.
CDC advises at least one HIV test in a lifetime for everyone aged 13 to 64 as part of routine health care. The U.S. Preventive Services Task Force sets its screening range at 15 to 65. Both advise more frequent testing for people with ongoing risk factors, and both recommend screening as part of the routine prenatal panel, with a third-trimester repeat in areas with elevated perinatal transmission. Sexually active gay and bisexual men may benefit from testing every three to six months.
A once-in-a-lifetime test for every adult is a screening recommendation, not a judgment about behavior. HIV frequently causes no symptoms for a decade or longer, so symptoms cannot tell anyone whether they have it.
The agency states that being diagnosed early and starting treatment right away leads to better health outcomes and reduces the chances of transmission. That second part matters. People who take antiretroviral therapy as prescribed and maintain an undetectable viral load do not transmit HIV to sexual partners, summarized as undetectable equals untransmittable. Someone who does not know their status cannot access that protection.
Free and Low-Cost Options Across the Country
The least-known option is a federal mail program. Through the CDC-funded Together TakeMeHome initiative, anyone 17 or older in the United States or Puerto Rico can order a pack of two free HIV self-tests every 90 days, regardless of insurance or immigration status. The form takes a few minutes, kits arrive in discreet packaging within a few days, and one test is meant to be shared with a partner or friend.
The program is larger than its profile suggests. It has distributed more than a million self-tests since launching in 2023, and CDC reporting on its first year found that roughly 40,000 people who ordered a kit had never been tested for HIV before.
The program offers oral swab and fingerstick tests, not one product. The OraQuick oral swab version is available through the program to people 17 and older, while the INSTI fingerstick version is approved for 18 and up. Which one is offered can depend on ZIP code. The FDA has separately expanded OraQuick's approved age range down to 14, though the mail program has not changed its own minimum.
For in-person testing, CDC maintains a national locator at gettested.cdc.gov listing sites by ZIP code, many offering free rapid tests with results in about 20 minutes. Local health departments, federally qualified health centers, Planned Parenthood affiliates, and many college health services test at no cost or on a sliding scale.
Insurance covers more than most people realize. HIV screening is a preventive service most plans must cover without cost sharing, so a clinician-ordered test typically carries no copay. Anyone billed for one should ask the plan why, since coding errors are appealable. Self-tests can also be bought over the counter without a prescription, and HIV.gov maintains a guide to testing options.
Reactive Result Is Not a Diagnosis
This is the part that causes the most fear and confusion, and it is worth understanding before opening a kit.
A self-test showing a positive line produces what is properly called a reactive or preliminary positive result. It is not a diagnosis. It means the test detected something requiring laboratory confirmation, which is necessary in every case.
False positives occur. The FDA-approved oral self-test has very high specificity, but no screening test is perfect, and a reactive result always goes to a laboratory before anyone is told they have HIV.
Anyone with a reactive result should contact a clinician, health department or community health center promptly to arrange confirmation. Those sites can also begin linkage to care right away, and 83.1 percent of people diagnosed in 2024 were linked to medical care within one month.
Waiting is difficult. Anyone who feels frightened can reach the Crisis Text Line by texting 741741, a resource the mail program itself points to, and local HIV service organizations provide counseling at no charge.
Window Periods, False Negatives and PrEP
A negative result carries more caveats than most people expect, and they matter more than the reactive-result caveats because negative results are far more common.
The first is sensitivity. Together TakeMeHome states plainly that about 8 out of 100 people who have HIV will still get a negative result on the self-test. That is not a reason to avoid self-testing, which reaches people who would otherwise never test at all, but it is a reason to treat a single negative self-test as reassuring rather than conclusive if there has been a specific exposure.
The second is timing. Every HIV test has a window period, the interval between infection and when a test can reliably detect it. For the oral fluid antibody self-test, that window is about three months, and the program advises anyone testing sooner after a possible exposure to retest 90 days after that exposure.
Antibody tests look for the immune response rather than the virus itself. Laboratory antigen and antibody tests and nucleic acid tests detect infection earlier, so anyone with a specific recent exposure should say so when seeking testing and ask for a laboratory test rather than relying on a swab.
One exception applies to people taking PrEP. Antiretroviral medication can delay a test's ability to detect infection, and self-tests are not recommended for people on PrEP because of lower sensitivity for recent infection. They should test through their prescribing clinician.
Self-tests screen only for HIV, not syphilis, gonorrhea, chlamydia, or hepatitis, so anyone testing after a possible exposure should ask about screening for those as well.
Steps After a Result in Either Direction
A negative result is an opportunity rather than an endpoint. People with ongoing risk can ask a clinician about PrEP, which is highly effective at preventing HIV and comes as a daily pill or a long-acting injection. Most plans cover it without cost sharing.
A confirmed positive result is the beginning of treatment, not a crisis to face alone. Modern therapy is typically one pill a day, frequently achieves viral suppression within months, and allows a normal life expectancy. Among people diagnosed in 2024, 71.1 percent reached viral suppression within six months. The Ryan White HIV/AIDS Program covers care for people who are uninsured or underinsured, and every state runs an AIDS Drug Assistance Program.
Nobody should delay testing over cost or immigration status. The federal mail program requires neither.
The bottom line: roughly one in eight Americans living with HIV is undiagnosed, CDC recommends at least one test for everyone aged 13 to 64, free kits can be mailed anywhere in the country, a reactive self-test result requires laboratory confirmation, and a negative result within three months of an exposure should be repeated.
Key Questions Answered
Who should get an HIV test? CDC advises at least one test in a lifetime for everyone aged 13 to 64 as part of routine care, and the U.S. Preventive Services Task Force sets its range at 15 to 65. Both advise more frequent testing with ongoing risk, and screening during pregnancy.
Where can someone get a free test? The CDC-funded Together TakeMeHome program mails two free self-tests to anyone 17 or older in the United States or Puerto Rico every 90 days, regardless of insurance or immigration status. The locator at gettested.cdc.gov lists in-person sites, many of them free.
How does an at-home test work? The program offers two types. The OraQuick oral swab version uses a swab of the upper and lower gums placed in a vial of solution, with results in 20 to 40 minutes. The INSTI version uses a drop of blood.
What does a reactive result mean? It is a preliminary positive, not a diagnosis. Laboratory confirmatory testing is required, and false positives do occur.
Can a negative result be wrong? Yes, in two ways. About 8 out of 100 people who have HIV will get a negative self-test result, and testing within the roughly three-month window period can also miss a recent infection. Retest 90 days after a possible exposure.
Should people taking PrEP use a self-test? No. Antiretroviral medication can delay detection, and self-tests are not recommended for people on PrEP. They should test through their prescribing clinician.
What happens after a confirmed positive result? Treatment usually begins quickly and is often one pill a day. Among people diagnosed in 2024, 83 percent were linked to care within a month. The Ryan White HIV/AIDS Program and state AIDS Drug Assistance Programs cover care for people who are uninsured or underinsured.
