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.

Mycoplasma genitalium is a bacterium that can infect the urinary and genital tract. Many people have never heard of it. It is rarely on a standard test panel, and the guidance on when to test for it is narrower than for most other infections.

This guide covers what the organism is, what research suggests about it, what mycoplasma genitalium symptoms can look like, and how testing and treatment work. It also covers where to start in New York City.

What mycoplasma genitalium is

Mycoplasma genitalium is a very small bacterium. It belongs to a group of organisms that have no cell wall. That is a basic feature of its biology, and it matters for treatment, as explained below.

The CDC STI Treatment Guidelines (2021) describe it as a sexually transmitted organism. It is associated with urethritis (inflammation of the urethra) in people with a penis. It is also associated with cervicitis and pelvic inflammatory disease in people with a cervix and uterus.

People often shorten the name to M. genitalium or Mgen. All three refer to the same organism.

The biology in plain terms

This is not a product or an ingredient, so there is no chemical formula to list. The useful science is about the organism itself.

No cell wall. Antibiotics that work by attacking a bacterial cell wall have nothing to act on here. That is one reason a clinician cannot simply reuse the treatment chosen for other infections.
Very small genome. Research suggests it has one of the smallest genomes of any bacterium that can reproduce on its own. It depends heavily on the cells it infects.
Slow growth. It grows slowly and is hard to culture in a laboratory. For that reason, modern testing looks for its genetic material instead of trying to grow it.
Genetic changes that affect treatment. The CDC guidelines note that the organism can develop changes that make some antibiotics less effective. Laboratories can sometimes detect those changes.

Research findings, framed as observations

Researchers are still learning about this organism. These are observations, not conclusions.

The CDC guidelines describe M. genitalium as a cause of persistent or recurrent urethritis. Research suggests it is found in a meaningful share of people with that picture.
Studies summarized by the CDC suggest an association with cervicitis. They also suggest an association with pelvic inflammatory disease, though the link is less clear than for chlamydia or gonorrhea.
Research suggests many infections cause no symptoms. In some people the organism may clear without treatment, but studies have not shown how often.
The CDC notes that antibiotic resistance has been increasing. This is the main reason testing and treatment for M. genitalium are handled differently from chlamydia.

The CDC does not publish a window period for M. genitalium testing the way it does for HIV. A clinician can tell you how to time a test for your situation.

Mycoplasma genitalium symptoms

Mycoplasma genitalium symptoms overlap with those of other infections. That is why symptoms alone cannot say which infection is involved. Only a clinician and a lab test can do that.

Symptoms that the CDC associates with M. genitalium include:

In people with a penis: burning when urinating, or discharge from the penis (urethritis).
In people with a cervix: unusual discharge, bleeding between periods or after sex, or pain during sex (cervicitis).
Lower abdominal or pelvic pain, which can be a sign of pelvic inflammatory disease.
Rectal discomfort in some people, though research on this is still limited.

Many people have no symptoms at all. The same symptoms also occur with chlamydia and gonorrhea. Our guide to chlamydia symptoms, testing and treatment in New York City explains how those overlap.

When CDC recommends testing

The CDC STI Treatment Guidelines (2021) recommend testing for M. genitalium in specific situations. They do not recommend it for everyone.

Persistent or recurrent urethritis. This means symptoms that continue or return after a clinician has treated the usual causes.
Persistent or recurrent cervicitis. The same logic applies.
Sometimes in pelvic inflammatory disease. The CDC guidelines advise considering it.
Partners of someone with a confirmed M. genitalium infection. The guidelines address how a clinician may handle partners.

The CDC does not recommend routine screening of people who have no symptoms. It also does not recommend testing everyone who is being tested for other STIs. A clinician can say whether your situation fits one of these categories.

Why it is not on standard panels

A standard STI panel usually covers chlamydia, gonorrhea, syphilis and HIV, and sometimes trichomoniasis or hepatitis. M. genitalium is typically left off for a few reasons.

No screening recommendation. Because CDC does not advise screening people without symptoms, there is little reason to add it to a routine panel.
Testing is limited. It requires a molecular test, and not every lab offers one. The CDC guidelines note that tests available in the United States are limited.
Treatment is complicated. Finding the organism without a plan for resistance-guided treatment can lead to treatment that does not work.

If you are not sure whether to ask for it, describe your symptoms and their timeline. Say what treatment you have already had. A clinician can then decide whether the test fits.

Resistance-guided treatment

The CDC guidelines describe treatment that is guided by resistance testing where it is available. In plain terms, the lab looks for genetic changes that make certain antibiotics less likely to work. The clinician then chooses what to prescribe based on that result.

Treatment is only what a clinician prescribes. The CDC describes a sequence of antibiotics rather than a single one for many cases. Details such as which medicines, how long and in what order depend on the lab result and your health history. Do not use leftover antibiotics or a partner's prescription.

Research suggests that treatment that does not match the resistance pattern can fail. It can also make resistance more likely. A clinician may suggest a follow-up visit to confirm that treatment worked. Follow their advice, since the CDC notes that treatment failure is a concern with this organism.

M. genitalium is a bacterial infection and is curable with the right treatment from a clinician.

Safety profile and contraindications

Because no product is involved, safety here means the safety of testing and treatment.

Testing. The test uses a urine sample or a swab. For people with a cervix, a swab may be collected by a clinician or by the patient. It poses very little risk.
Treatment. Antibiotics can cause side effects, and some are not suitable in pregnancy or with certain other medicines or conditions. Tell the clinician if you are pregnant, may become pregnant, or take other medicines.
Pregnancy. The CDC guidelines have limited information on M. genitalium in pregnancy. A prenatal care provider should guide decisions.
Doxy-PEP. The CDC's 2024 guidance on doxycycline after sex addresses syphilis, chlamydia and gonorrhea. It does not present doxy-PEP as a way to prevent M. genitalium. Ask a clinician how it applies to you.
Sex during treatment. A clinician will say when it is safe to resume. Condoms and avoiding sex until treatment is complete are common advice.

Quality indicators when choosing where to test

There is no product to source here. The real quality question is whether a clinic can order the right test and act on the result. These questions can help.

Does the clinic run a molecular test for M. genitalium, or send it to a lab that does?
Does the lab report resistance results, and how long do they take?
Will a clinician review the result with you and prescribe treatment if needed?
Is follow-up testing available if symptoms continue?
How are partners handled?

For other STIs, the Department of Health also notes that some New York State partner treatment rules exist. New York Public Health Law § 2312 covers expedited partner therapy. NYC Health says the infections for which CDC recommends it are chlamydia, gonorrhea and trichomoniasis. M. genitalium is not named in that list, so ask your clinician about partners.

Where to start in New York City

The NYC Department of Health and Mental Hygiene runs Sexual Health Clinics. NYC Health says these clinics offer low- to no-cost care, and that no one is turned away for inability to pay. Adults 19 and older are asked for insurance or a sliding-scale fee, and no proof of income is required. Most services are walk-in, and clinics may close early once they reach capacity.

The clinic pages do not say which clinics run an M. genitalium test. Call the Sexual Health Clinic Hotline at 347-396-7959 (Monday to Friday, 9 a.m. to 3:30 p.m.) and ask before you go. The Health Department's Sexual Health Clinics page lists current locations and hours.

Open clinics named on that page include:

Chelsea Sexual Health Clinic, 303 9th Avenue, Manhattan. Monday to Friday, 8:30 a.m. to 3:30 p.m.
Central Harlem Sexual Health Clinic, 2238 Fifth Avenue, Manhattan. Monday to Friday, 8:30 a.m. to 3:30 p.m.
Fort Greene Sexual Health Clinic, 295 Flatbush Avenue Extension, Brooklyn. Monday to Friday, 8:30 a.m. to 3:30 p.m.
Morrisania Sexual Health Clinic, 1309 Fulton Avenue, the Bronx. Monday to Friday, 8:30 a.m. to 3:30 p.m.
Jamaica Sexual Health Clinic, 90-37 Parsons Boulevard, Queens. Monday to Friday, 8:30 a.m. to 3:30 p.m.
Corona Sexual Health Clinic, 34-33 Junction Boulevard, Queens. Monday to Wednesday and Friday, 8:30 a.m. to 3:30 p.m.; Thursday, 8:30 a.m. to 7:15 p.m.

NYC Health says the Crown Heights and Riverside clinics are closed until further notice. It also lists no Health Department sexual health clinic on Staten Island. You can compare these with the full local testing list, and our overview of STD testing in New York City explains the other options.

Other places

Callen-Lorde Community Health Center. This LGBTQ+ community health center is at 356 W 18th St in Chelsea (212-271-7200). It says it provides services regardless of ability to pay, with a sliding fee for people who are uninsured or underinsured. Sexual health visits are by appointment on weekdays with limited walk-in, and there is a Saturday walk-in from 9 a.m. to 3 p.m. Callen-Lorde also has sites in the Bronx and Brooklyn. Call to confirm testing options.
Mount Sinai Adolescent Health Center. This is at 312-320 East 94th Street (212-423-3000). It serves young people ages 10 to 26 and says its services are completely free. Walk-in hours are Monday to Saturday, 8:30 a.m. to 4 p.m.

Young people

New York Public Health Law § 2305 lets a licensed physician diagnose and treat a person under 21 who has or may have been exposed to an STD without parental consent. NYC Health says its Sexual Health Clinics serve anyone 12 or older without parental consent, regardless of immigration status.

Another way to find a site

The CDC's GetTested locator can help you find testing near any address in the city. Call ahead to ask about the specific test, since the locator does not list every test offered.

Questions to bring to a visit

Do my symptoms and history fit the CDC's reasons to test for M. genitalium?
Which tests are you running today, and which are not included?
If the result is positive, will resistance testing guide my treatment?
When should I come back, and when can I have sex again?
What should I tell my partners?

The bottom line

M. genitalium is a real but often overlooked infection. Mycoplasma genitalium symptoms look like those of more common infections, and testing is aimed mainly at people whose symptoms persist or return. If that sounds familiar, a free or low-cost visit at a New York City clinic is a reasonable next step. A clinician can explain which tests apply to you.

Mycoplasma Genitalium: What It Is and Where to Get Tested in New York City