This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

Free STD testing exists in San Antonio, and you do not need to be in a crisis to use it. Several nonprofits and one public clinic test for common infections at no charge or at a reduced cost. This guide walks you through how to choose one, what to bring, what to expect, and how to check that the details are still current.

Each step is short and can be done in order. If you already know where you want to go, skip ahead to the clinic list in Step 3.

Why free and low-cost testing matters here

The CDC STI Treatment Guidelines (2021) recommend routine screening for many people, even when they have no symptoms. Many infections cause no symptoms at all, so a test is often the only way to learn your status.

Local numbers are one reason clinics here stay busy. The Texas Department of State Health Services (DSHS) 2022 STD Surveillance Report counted 12,305 chlamydia cases and 5,983 gonorrhea cases in Bexar County. The county gonorrhea rate was 290.5 per 100,000 people, compared with 207.0 for Texas that year. The same report listed 500 primary and secondary syphilis cases in Bexar County, a rate of 24.3 per 100,000, against 15.5 statewide.

For HIV, the CDC HIV Surveillance Data Release Tables for 2024 show a Bexar County rate of 21.1 new diagnoses per 100,000 people aged 13 and older. DSHS notes that figures can shift slightly as data are cleaned.

These numbers describe a community, not you. They are a reason to know where free testing is, not a reason to worry.

What you need before you start

A photo ID. The Metro Health STI Walk-In Clinic requires a current photo ID. Other sites may ask for one too, so it helps to have it with you.
A list of your questions. Write down any symptoms, the dates of recent partners if you know them, and anything you want checked.
Your medication and allergy list. A clinician may want to know what you take.
Insurance information, if you have it. Some sites bill insurance or use it to set fees. Many free sites do not require it.
Proof of income, for sliding-scale clinics. CommuniCare and CentroMed set fees by income, so ask which papers they accept.
A phone you can answer. Some results arrive by call or through a portal.
About an hour. Walk-in lines can be long, and check-in may close early on busy days.

Step-by-step: how to get free STD testing in San Antonio

Step 1: Decide what you want to be tested for

Different tests cover different infections. Common ones include HIV, syphilis, gonorrhea and chlamydia. Some sites also offer hepatitis C testing.

The CDC STI Treatment Guidelines (2021) recommend yearly chlamydia and gonorrhea screening for sexually active women under 25, and for older women with risk factors such as a new partner. The same guidelines recommend at least yearly screening for gay, bisexual and other men who have sex with men, and more often for some people with higher exposure. The U.S. Preventive Services Task Force (USPSTF) recommends HIV screening for everyone aged 15 to 65.

Not sure what fits your situation? The CDC's GetTested locator can show testing sites, and a clinician at any site below can talk through what makes sense for you. Every gender and orientation is welcome at these clinics.

Step 2: Think about timing

A test can only detect an infection after enough time has passed since exposure. This is called the window period.

For HIV, the CDC says a nucleic acid test can usually detect HIV 10 to 33 days after exposure. An antigen/antibody test done on a blood draw usually detects it 18 to 45 days after exposure. Fingerstick antigen/antibody tests may take 18 to 90 days. Antibody-only tests can take 23 to 90 days.

For other infections, windows vary. Ask the clinician at your visit whether a repeat test later would be useful. Seeking a first test sooner is still reasonable, and the clinician can tell you whether to come back.

If you think you were recently exposed to HIV, the CDC says post-exposure prophylaxis (PEP) has to start within 72 hours. A clinician decides whether it fits your situation. Alamo Area Resource Center and Kind Clinic both list PEP among their services, so call quickly.

Step 3: Pick a clinic from the options below

Here is every free or sliding-scale option published for San Antonio, with who it serves and what the sources say. For a fuller directory, see our guide to where to get tested in San Antonio.

Free testing sites

San Antonio AIDS Foundation (SAAF)

Address: 818 E. Grayson Street, San Antonio, TX 78208
Phone: (210) 225-4715
Tests listed: rapid HIV, syphilis, gonorrhea and chlamydia. SAAF's testing page says screening and confirmatory services are free and no appointment is needed.
Results: SAAF says gonorrhea and chlamydia results come back in 7 to 10 days from the DSHS lab.
Hours listed: Mon 8:30 to 4:00; Tue 12:00 to 8:00; Wed and Thu 8:30 to 4:00; Fri 9:00 to 1:00; Sat 11:00 to 3:00; closed Sunday.
Also lists: PrEP and doxy-PEP.
SAAF testing page

Alamo Area Resource Center (AARC)

Address: 303 N. Frio, San Antonio, TX 78207
Phone: (210) 625-7200
Tests listed: free testing for HIV, hepatitis C, syphilis, gonorrhea and chlamydia. Rapid HIV, syphilis and hepatitis C tests use a fingerstick.
Walk-ins: AARC says Monday through Friday 8 a.m. to 4:30 p.m., and Wednesday until 8 p.m.
Also lists: PrEP, PEP and at-home self-test kits. The page does not say whether kits are mailed or picked up, or who qualifies, so call the number above.
AARC testing page

Kind Clinic, San Antonio (Isom)

Address: 730 Isom Road, San Antonio, TX 78216
Phone: Kind Clinic lists a general support line, 833-937-5463, and no number specific to this location.
Services listed: HIV and STI testing, STI treatment, HIV care, PrEP and PEP. Kind Clinic's 2024 announcement describes walk-in testing, and it says testing is free.
Clinic hours listed: Mon, Tue and Fri 9:00 a.m. to 5:00 p.m.; Wed and Thu 9:00 a.m. to 8:00 p.m.; 2nd and 4th Saturdays 9:00 a.m. to 2:00 p.m. Kind Clinic notes that walk-in testing hours differ from clinic hours, so confirm before you go.
Note: Kind Clinic says doxy-PEP is available to its own patients only.
Kind Clinic locations

BEAT AIDS

Phone: 210.212.2266
Services listed: BEAT AIDS says it offers free, confidential HIV testing and PrEP, plus confidential testing and treatment for common STIs.
Location: The organization's site lists several San Antonio locations but does not say which one does testing. Call before you go and ask for the testing address and whether walk-ins are accepted.
BEAT AIDS

Low-cost and sliding-scale options

Metro Health STI Walk-In Clinic

Operator: San Antonio Metropolitan Health District (Metro Health)
Address: 512 E. Highland, Suite 150, San Antonio, TX 78210
Phone: 210-207-8830
Cost: Metro Health lists a $15 office visit administrative fee, and says other fees vary by service. This clinic is low cost, not free.
Who qualifies: Metro Health says residents of San Antonio and Bexar County, and people with no other way to get STI services.
Bring: A current photo ID. Metro Health says testing here is not anonymous.
Hours listed: Mon to Thu 7:45 a.m. to 4:30 p.m. (latest check-in 3 p.m.); Fri 7:45 a.m. to 12:00 p.m. (latest check-in 10:30 a.m.). Check-in may close early when the clinic is at capacity.
Services: University Health's sexual health page lists STI and HIV testing, treatment and counseling.
Metro Health STI Walk-In Clinic

CommuniCare Apollo Wellness Clinic

Address: 6511 W Loop 1604 N, Ste. 105, San Antonio, TX 78254
Phone: (726) 224-3438
Cost: CommuniCare says self-pay patients with family income under 200% of the federal poverty guidelines can get a sliding fee discount.
Hours listed: Mon to Fri 8:00 a.m. to 5:00 p.m. The page does not say whether walk-ins are accepted, so call first.
Services listed: STD and HIV screening and testing, and PrEP.
CommuniCare STD and HIV testing

CentroMed

Phone: 210-922-7000
Services listed: CentroMed's women's health page lists screening and treatment for sexually transmitted diseases.
Cost: CentroMed says it uses a sliding fee scale based on income and family size and does not deny care because of inability to pay.
Location: CentroMed runs several clinics, and its page does not say which ones test. Call and ask. Its administration office is at 3750 Commercial Ave, San Antonio, TX 78221.
CentroMed women's health

Free testing you can start from home

If getting to a clinic is hard, there are public programs that mail free tests.

Test for Texas (DSHS): DSHS says anyone in Texas aged 13 or older can order free mailed kits for HIV, syphilis, gonorrhea and chlamydia, with no insurance needed. Results appear in a secure portal seven business days after the sample reaches the lab. Details are on the DSHS free at-home testing page.
Together TakeMeHome (CDC-funded): Its FAQ says it mails free HIV self-tests to anyone 17 or older in the U.S. (the fingerstick option is for ages 18 and up). Each package holds two self-tests, and you can reorder every 90 days. See the program FAQ.

A home test is a first look. A clinician can explain any result and arrange follow-up care.

Step 4: Check current hours and rules before you go

Hours, fees and walk-in rules change. Before you leave home:

Open the clinic's own page, linked above, and look for a date or a banner about holiday or short-staff closures.
Call the number listed and ask three questions. Is the testing site open today? Do I need an appointment or an ID? Is there a fee for the tests I want?
Ask about arriving early. Metro Health notes that check-in can close before the posted end of the day.

If a page does not publish a price or a walk-in policy, the clinic or health department is the one to ask. You can also confirm services through the Metro Health STI and HIV page.

Step 5: Go to your visit

At the clinic, expect to check in, answer a few questions, and give a sample. Depending on what you are tested for, that may be a urine sample, a swab, a fingerstick or a blood draw. You can ask the staff which sample is used for which test.

The questions are about your health and are not about judging you. You can say which body parts you want checked, because a urine test alone may not cover the throat or rectum for some infections. A clinician can explain what is right for you.

Texas law is clear about minors. Under Texas Family Code Section 32.003, a minor of any age may consent to diagnosis and treatment of a reportable infectious disease, and parent or guardian consent is not needed. The same law lets a physician tell a parent or guardian about the treatment, with or without the minor's consent. So a teen should ask the clinic about its privacy practices before the visit. DSHS's "HIV and Texas Law" publication says minors may consent to HIV care as well.

Step 6: Ask how you will get your results

Before you leave, ask:

How will I hear back: phone, portal or in person?
How long will it take?
Who do I call if I do not hear by then?

Rapid fingerstick tests can give a reading during the visit. Lab tests take longer. SAAF, for example, says gonorrhea and chlamydia results take 7 to 10 days.

Texas requires labs and clinicians to report certain infections to public health. DSHS's 2026 notifiable conditions list includes chlamydia, gonorrhea, syphilis, HIV and AIDS. Reports go to health departments, which use them for tracking and to link people to care. Ask the clinic to explain what is reported and how it is handled.

Step 7: Plan your next step

Whatever the result, ask what comes next. If a test shows an infection, bacterial STIs and trichomoniasis can be cured with treatment prescribed by a clinician. HIV, herpes and HPV cannot be cured, but they can be treated and managed. Treatment details, including which medicine and how long, are decided by the clinician for your situation.

If you test positive for something treatable, Texas has a way for partners to be treated too. The CDC's page on expedited partner therapy in Texas says state rules let a clinician prescribe for the partner of an established patient, and pharmacists may dispense those prescriptions. Ask your clinician whether it applies to you.

You may also ask about prevention:

PrEP for HIV prevention. The Metro Health PrEP Clinic (512 E. Highland Blvd., Ste. 150; 210-207-7292) has a nurse practitioner, in-clinic labs and a PrEP Navigator for insurance and cost help. Walk-ins are accepted, and Metro Health encourages appointments.
Doxy-PEP. The CDC's 2024 guidance covers doxycycline after sex for some people, and a clinician decides who it fits. SAAF lists it, and Kind Clinic offers it to its own patients.

Tips for a smoother visit

Go early in the day. Walk-in clinics fill up, and Metro Health says check-in may close early at capacity.
Ask for a full panel. If you are not sure what is included, ask the staff to list the infections covered.
Bring a friend if it helps. Some people feel calmer with company in the waiting room.
Write down results. Keep a note of the date, test and result for your own records.
Tell the clinic about your needs. Mention language, disability or privacy concerns so staff can help.
Pregnant? Texas Health and Safety Code Section 81.090 calls for syphilis, HIV and hepatitis B tests at the first prenatal visit, and syphilis and HIV tests in the third trimester (not earlier than the 28th week). A person may object to the HIV tests. Metro Health says syphilis testing for pregnant women is available at its walk-in clinic.

Common mistakes to avoid

Assuming "free" is the same everywhere. SAAF, AARC, Kind Clinic and BEAT AIDS list free testing. Metro Health lists a $15 visit fee. CommuniCare and CentroMed use sliding fees. Ask before you go.
Arriving too late. Metro Health's latest check-in times are earlier than closing time.
Forgetting ID. Metro Health requires a photo ID and does not do anonymous testing.
Relying on an old hours listing. Kind Clinic's walk-in hours were posted in a 2024 announcement and its locations page now says they differ from clinic hours. Call.
Testing too early and stopping there. If your exposure was recent, ask a clinician when to test again.
Skipping follow-up. A result is only useful if you know how to get it, and what to do next.
Delaying out of embarrassment. Testing is routine healthcare, and staff at these sites do it every day.

What to expect from your results

Results can come in several forms, and a clinician can explain each one.

Negative. This means the test did not detect the infection in the sample at that time. Depending on when the exposure happened, a clinician may suggest testing again.
Positive. This means the test detected signs of an infection. A clinician usually confirms it and discusses care. Many infections can be treated, and HIV can be managed with ongoing treatment from a clinician.
Unclear or invalid. Sometimes a sample needs to be repeated. That is common and does not mean something is wrong.

No test is perfect. Results may be affected by timing, sample quality and the type of test, which is why follow-up questions matter.

A note on privacy and the law

Some readers worry about what testing could mean for them legally. According to the CDC's 2023 analysis of state laws, Texas has no HIV-specific or STD-specific criminal exposure law. General criminal laws can still apply in some situations. If you have concerns, a clinic counselor can talk through them in confidence, and a legal aid organization can answer legal questions.

The short version

To get free STD testing in San Antonio:

Choose what you want tested.
Think about timing.
Pick a site that fits your schedule and budget.
Call to confirm hours, fees and ID rules.
Go, ask about results and get a plan for next steps.

If you would like another way to find sites, the CDC's gettested.cdc.gov lets you enter your zip code. Free and low-cost testing is available. You can take the first step today.

Free STD Testing in San Antonio: Every Free and Sliding-Scale Option