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 in Houston is real, and it comes in more than one form. The city and Harris County run public clinics. Community health centers offer free rapid tests. A state program mails free kits to your door.

This guide walks you through the options step by step. It covers who each one serves, what to bring and how to check that a clinic is open before you go. It does not tell you which test you personally need. A clinician can help you decide that.

What you need before you start

You do not need much. Most places accept people without insurance, and none of the free options listed here ask you to pay for the tests they describe.

A phone. Calling ahead is the most reliable way to confirm hours and services.
Photo ID, if you have one. Policies differ by clinic, so ask when you call whether ID is required.
Insurance card, if you have one. Having insurance is not required for the free options below.
A short list of your questions and any symptoms. A few notes help the visit go faster.
A list of medicines you take. A clinician may ask.
A way to receive results. That means a working phone number or a patient portal you can reach. Ask the clinic how results are shared.

If you are in a hurry, the local testing list shows the Houston options in one place.

Step 1: Decide which kind of testing fits your situation

There are three broad routes. Each suits different needs.

A clinic visit. Staff can talk with you, collect samples and discuss treatment if a test comes back positive.
A rapid test at a community site. These sites list rapid HIV, hepatitis C and syphilis testing. They do not describe a full panel.
A home kit or a mobile visit. These are useful if travel or time is the barrier.

The CDC STI Treatment Guidelines (2021) note that the right tests depend on your age, your sexual history and which body sites may have been exposed. You can describe your situation to a clinician and they can recommend the tests.

CDC also runs a locator at gettested.cdc.gov. You can use it alongside the options below.

Step 2: Review every free and sliding-scale option in Houston

Everything in this section comes from the clinics and agencies themselves. The table gives a quick comparison. The sections after it add detail.

Option	Cost as published	What it lists	Walk-in
Houston Health Department health centers (Northside, Sharpstown, Sunnyside)	Sliding scale	STD testing, HIV testing, PrEP, nPEP, treatment	As capacity permits
Harris County Public Health Antoine Clinic	Free	HIV, syphilis, gonorrhea and chlamydia testing, rapid HIV testing, PrEP, STI treatment	Walk-ins welcome
Legacy Community Health, Montrose	HIV, syphilis and hepatitis C testing free; full panel pricing not stated	STI testing, HIV, hepatitis C, PrEP, nPEP, doxy-PEP, treatment	Walk-in for HIV, syphilis and hepatitis C
Avenue 360 Heights and Midtown	Free rapid testing	Rapid HIV, hepatitis C and syphilis	Walk-ins welcomed
The Montrose Center	Free	Rapid HIV, hepatitis C and syphilis	Free walk-in testing
Test for Texas (mail kit)	Free	HIV, syphilis, gonorrhea and chlamydia	Order online

Houston Health Department health centers

The Houston Health Department lists STD care and testing at three centers. All three use a sliding-scale fee, which means the cost depends on what you can pay. All three share the phone number 832-393-4220.

Northside Health Center, 8504 Schuller Rd., Houston, Texas 77093
Sharpstown Health Services, 6201 Bonhomme Rd., 3rd Floor, South Tower, Houston, Texas 77036
Sunnyside Health and Multi-Service Center, 4410 Reed Rd., Houston, Texas 77051-2718

The Houston Health Department says it accepts walk-ins as capacity permits, and that appointments are encouraged from September 1, 2026. A walk-in is not guaranteed to be seen, so a call first is wise. The department also lists PrEP and nPEP at these centers by appointment at 832-395-9800.

Harris County Public Health Antoine Clinic

The Antoine Clinic is at 5815 Antoine Dr, Houston, TX 77091. The phone number is 832-927-7350. Harris County Public Health lists services as free and says uninsured people are welcome.

The clinic lists testing for HIV, syphilis, gonorrhea and chlamydia, plus PrEP prescriptions and STI treatment. Its End HIV testing page says walk-ins are welcome.

Harris County Public Health lists these hours: Monday to Thursday, 8am to 7pm; Friday, closed; every other Saturday, 8am to 2pm. Confirm them before you go, because the "every other Saturday" schedule is easy to misread.

Legacy Community Health, Montrose

Legacy Community Health in Montrose is at 1415 California St., Houston, TX 77006. The phone number is (832) 548-5100. Legacy lists HIV, syphilis and hepatitis C testing as free. It says its services are open to all regardless of ability to pay.

Walk-in testing covers HIV, syphilis and hepatitis C. A full STI panel is offered as appointments are available. Legacy also lists an express STI testing service for uninsured patients who have no symptoms. The price of a full panel is not stated on the pages we reviewed, so ask when you call.

Legacy also lists PrEP, nPEP and doxy-PEP. Doxy-PEP is a medicine a clinician may prescribe after certain exposures. The CDC issued guidance on it in 2024. A clinician decides whether it fits your situation.

Avenue 360 Health & Wellness

Avenue 360 offers free walk-in rapid HIV, hepatitis C and syphilis testing at two Houston locations. Its testing page lists Monday to Friday, 8:30am to 4:30pm.

Heights (Main Campus), 2150 West 18th Street, Suite 300, Houston, TX 77008
Midtown, 2920 Fannin St., Houston, TX 77002

The phone number for both is (713) 426-0027. The pages we reviewed describe rapid syphilis testing, not a full STI panel. Avenue 360 says walk-in rapid testing at its Spring Cypress location is suspended because of a temporary closure.

The Montrose Center

The Montrose Center is an LGBTQ+ community center at 401 Branard Street, Houston, Texas 77006. The phone number is 713-529-0037. It lists free walk-in testing Monday to Thursday, 9AM to 2PM. Services are rapid HIV, hepatitis C and syphilis testing.

The center says it does not offer a full STI panel or PrEP. If you want those, another clinic on this list can help.

Free testing from home or at a place you choose

These options help if getting to a clinic is hard.

Test for Texas. The Texas Department of State Health Services lists a free mail-order self-collection kit for anyone in Texas aged 13 or older. It covers HIV, syphilis, gonorrhea and chlamydia. No insurance is needed. You order at the DSHS testing page, which links to testfortexas.org.
Together TakeMeHome. This program offers a free pack of two HIV self-tests for U.S. residents aged 17 or older, once per 90 days. The Houston Health Department links to it from its HIV and STI page. Find it at together.takemehome.org.
Legacy at-home rapid HIV test. Legacy lists a free at-home rapid HIV test, mailed after a phone screening and subject to availability. See the Legacy at-home testing page.
Harris County Public Health Testing123. This is free mobile HIV and syphilis testing at a location you choose in Harris or Montgomery County. Staff come to you, and it is not a mail kit. Text (281) 962-8378. Details are on the End HIV testing page.

A kit tests only the infections it lists. Hepatitis C and several other infections are not on the Test for Texas list, so a clinic visit may still be useful.

Step 3: Choose a clinic and check current hours

Hours and walk-in rules change. A page that was right last month may be out of date now.

Pick two options. Choose the closest one and one backup. If you take public transit, check the route to each address.
Call the clinic. Use the number listed above. Ask whether walk-ins are being seen today, how long the wait usually is and when the last walk-in is accepted.
Check the official page. The clinic links in this guide go to the operator's own site. That is where schedule changes are usually posted.
Ask which tests are included. A "free test" can mean a rapid HIV test only. It may not include testing for chlamydia or gonorrhea. Ask exactly what is covered.
Ask about the fee if it is a sliding scale. Ask what documents they need to set your fee, such as proof of income.
Plan for the wait. A walk-in visit can take a while. Bring water and something to read.

For hours or prices this guide does not list, the clinic or the Houston Health Department has the current answer.

Step 4: Know your rights and privacy in Texas

Privacy worries stop some people from getting tested, so here is what Texas law says.

Minors can consent. Under Texas Family Code Section 32.003, a minor of any age may consent to diagnosis and treatment of a reportable infectious disease. Texas DSHS says this includes HIV. Parent or guardian consent is not required.
A parent may still be told. The same section allows a physician to tell a parent or guardian about the treatment. It is permitted, not required. Teens should ask a clinic how it handles this before a visit.
Parents may see portals. The Houston Health Department notes that Texas SB 1188, effective September 1, 2025, gives parents and guardians full access to a minor's electronic health record for ages 0 to 17. Ask the clinic what that means for results posted online.
Some results are reported to the state. Texas DSHS lists chlamydia, gonorrhea, syphilis and HIV as notifiable conditions. Clinics and labs report them to public health, and the reporting windows range from one work day to one week.
Criminal law. CDC's 2023 analysis places Texas in the category with no HIV-specific or STD-specific criminal exposure law. Texas has general criminal laws that can still apply. If you have questions about your own situation, a legal aid organization can help.

For pregnancy, Texas Health and Safety Code Section 81.090 sets out testing for syphilis, HIV and hepatitis B during prenatal care and at delivery. The person may object to the HIV tests but not the syphilis tests. A prenatal provider can explain the schedule.

Step 5: Go to your visit

Arrive with your items. Bring ID and insurance if you have them, plus your notes.
Expect some questions. Staff may ask about symptoms, partners and past testing. These questions help the clinician choose tests. They are not a judgment.
Say what you want to be tested for. You can ask about specific infections. You can also ask the clinician to recommend a set of tests.
Know what a sample might be. Depending on the test, it can be blood, urine, a swab or a finger-prick. A swab may be collected by you or by staff.
Ask how and when you will hear back. Ask which phone number or portal they will use and whether they will leave messages.
Ask about next steps. If a result is positive, ask how treatment works, where to get it and whether partners should be told.

Tips for a smoother visit

Go early in the day if you can. Walk-in capacity is limited, and Houston Health Department centers see walk-ins only as capacity permits.
Ask about the window period. A test may not detect a recent exposure. CDC explains that the time a test needs to detect an infection differs by infection and by test type. A clinician can tell you whether a repeat test is useful and when.
Ask about all body sites. The CDC guidelines say testing can include the throat, rectum and genitals depending on the sex people have. Mention this to the clinician.
Consider PrEP and PEP conversations. The Houston Health Department offers PrEP and nPEP, and staff help with co-pay and assistance programs. Legacy lists same-day PrEP walk-in, with eligibility specialists for low-cost or no-cost PrEP. Call (713) 814-3300 for that.
Bring a friend if it helps. Many people feel calmer with company.
Tell partners if you are comfortable. Texas allows physicians to prescribe medicine for the partners of an established patient under Texas Medical Board rules, according to CDC's page on expedited partner therapy in Texas. A clinician can explain how it works.

Common mistakes to avoid

Assuming one test covers everything. Rapid tests at community sites cover the infections they list. A full panel is a separate service at some clinics.
Skipping the phone call. Hours change, and appointments are now encouraged at Houston Health Department centers.
Relying on an old schedule. The Antoine Clinic is closed on Fridays and open on only some Saturdays, per Harris County Public Health. Confirm before you travel.
Not asking about results. Find out how you will be contacted so a missed call does not delay your results.
Waiting out of embarrassment. Clinic staff see these visits every day. They do not judge.
Promising a teen that no parent will ever know. Texas law lets a physician tell a parent. Ask the clinic about its practice first.
Using an affiliate or paid kit. The free options in this guide come from public agencies and local clinics. Use those.

What to expect from your results

Results look different depending on the test and the place.

Rapid tests. Rapid HIV, hepatitis C and syphilis tests at community sites may give a result during the visit. Ask the staff how quickly you can expect it.
Lab tests. Samples sent to a lab typically take longer. The clinic can tell you the usual timing.
A negative result. A negative result may mean the test did not detect an infection at that time. If you were exposed recently, a clinician may suggest testing again. Ask what timing makes sense.
A positive result. A clinician can explain what it means and confirm it if needed. Bacterial STIs and trichomoniasis are curable with treatment from a clinician. HIV, herpes and HPV are not curable, but they are treatable or manageable. Any treatment is chosen and prescribed by a clinician.
Follow-up. After treatment for some infections, a clinician may suggest retesting. Ask whether that applies to you.

No test is perfect. That is why it helps to ask a clinician how to read your own result.

Why testing in Houston matters

Public health data shows these infections are common in the Houston area. Texas DSHS reported 31,406 chlamydia cases in Harris County in 2022, a rate of 656.9 per 100,000 people. The Texas rate that year was 519.9 per 100,000. For gonorrhea, Harris County had 12,935 cases, or 270.6 per 100,000, against 207.0 for Texas, per the Texas STD Surveillance Report 2022.

The Houston Health Department reported 1,343 new HIV diagnoses in Houston and Harris County in 2023, a rate of 27.5 per 100,000.

These numbers are a reason to make testing routine. They say nothing about any one person. Many infections cause no symptoms, which is why CDC and USPSTF recommend screening for certain groups. A clinician can tell you which recommendations fit you.

Your next step

Pick one option from Step 2 and call today. If you are not sure where to begin, start with gettested.cdc.gov. You can also call the Houston Health Department at 832-393-4220 or the Antoine Clinic at 832-927-7350. Staff can tell you what is available now.

Free STD Testing in Houston: Every Free and Sliding-Scale Option