Skip to main content
King County logo

Appointments and limited walk-in availability. If you need HIV/STI testing and have symptoms or been exposed to HIV or a STI or need HIV/STI screening please call 206-744-3590 to make an appointment. Appointments and limited walk-in services are available Mon, Wed, Thurs and Friday 7:30-6:00 and Tuesdays 9:30-6:00. Walk-ins should arrive no later than 4:00 if they want to be seen that day.

  • Screening appointments will be scheduled no more than 2 business days in advance.
  • Telehealth visits (by phone or video) are also available. Please call.
  • We will maintain social distancing of 6 feet or more when possible, and will only allow 9 people in the waiting area. (NOTE: You may be asked to return at a later time if our waiting area is full).
  • Please wear a face mask throughout your visit.
  • Please stay home if you have any symptoms that could be COVID-19 (fever, cough, shortness of breath, sore throat, runny nose). Call your primary care doctor if you are concerned about your condition.

We look forward to seeing you.

Walk-in clinic hours

Ninth and Jefferson Building
908 Jefferson St, 11th Floor
Seattle, WA
Phone: 206-744-3590

  • Monday, 7:30 am to 6:00 pm
  • Tuesday, 9:30 am - 6:00 pm
  • Wednesday, 7:30 am - 6:00 pm
  • Thursday, 7:30 am to 6:00 pm
  • Friday, 7:30 am to 6:00 pm
  • Sat/Sun, closed

No appointment needed. We are a walk-in clinic. We encourage you to call ahead to check on wait times. Interpreters are available.

To be seen more quickly, print and bring the completed Registration Worksheet with you.

You will be seen regardless of your ability to pay. Payment for medical services is based on a sliding fee scale. Non-judgmental!

All are welcome!

Professional. Comprehensive. Confidential. Affordable.


We can help

If you think you might have symptoms of a sexually transmitted disease (STD), get tested and treated right away. Even if you do not have symptoms, you could have an STD. Come see us and get an STD checkup...and peace of mind.

Get tested and treated.
We provide confidential testing and treatment, and we can answer your questions about HIV and other STDs.

Get evaluated for PrEP.
Pre-Exposure Prophylaxis (PrEP) is a pill that can prevent HIV infection. It's for HIV negative people who are at risk of becoming HIV positive through sexual activity or injecting drugs.

Get help finding HIV care.
All people living with HIV in Washington State can get HIV medical care. We can connect you to the right medical provider.

Learn where else you can be tested.
Select Public Health Centers and community-based organizations that provide HIV and STD testing.

Quotes from our patients

I like that I can get tested and treated in one stop."

Everyone is professional and it seems community driven. I have recommended the clinic to my friends."

I was nervous when I first came in but almost immediately after sitting with the staff all my anxiety went away because they were so easy to talk to."

This office is a safe space for all people including lesbian, gay, bisexual, pansexual, asexual, straight, two-spirit, transgender, cisgender, queer, questioning, ally.

About us

Learn about the dedicated staff of the Sexual Health Clinic at Harborview Medical Center.

Dwyn Dithmer, Nurse Practitioner

Dwyn Dithmer, MS, ARNP, is a Board Certified Family Nurse Practitioner. Over the course of her 30 year career, she has worked in the clinic diagnosing and treating sexually transmitted infections. Additionally she recruits and enrolls participants in various STI related studies. She has Masters degrees from both Binghamton University (NY) and Pace University. Her Bachelor's degree is from Georgetown University.

Susannah Hermann, Nurse Practitioner

Susannah Herrmann graduated from the University of Washington Family Nurse Practitioner program in 2001. After a brief stint in family practice she worked in women's reproductive health for 10 years. Susannah joined the Sexual Health Clinic in 2006. She strives to create a safe space in which all patients feel welcome getting tested, treated, and discussing strategies for reducing risk. She is bilingual in English and Spanish.

Fred Matías, Registered Nurse

Fred Matías, BSN, RN, is a registered nurse who joined the Sexual Health Clinic in November 2018. He graduated in 2014 with his BSN from the University of Alabama in Huntsville. He has worked as a clinic nurse at an HIV clinic and at a TB clinic. He speaks English, Spanish, and Portuguese.

Erin Morton, Nurse Practitioner

Erin Morton, ARNP, is a Nurse Practitioner with the Sexual Health Clinic since 2021. Erin received her Master of Science in Nursing from the University of Pennsylvania in 2016. Since then, she has worked in the fields of sexual and reproductive healthcare, transgender care, and gynecologic oncology. She is passionate about health equity, and creating an environment where patients feel safe, heard, and empowered to be active partners in their healthcare.

Eduardo Munoz, Physician Assistant

Eduardo Munoz is a Physician Assistant who has worked at the Sexual Health Clinic since August 1, 1990.

Negusse Ocbamichael, PA-C, graduated from the University of Washington Medical School, PA program. His clinical experience and interests are in infectious diseases, reproductive and sexual health. For over 28 years, he has worked at the King County Sexual Health Clinic, University of Washington, Virology Research Clinic, HIV Prevention Trials Network and International medicine clinic at Harborview medical center, as a clinician, researcher and administrator. He also served as a Faculty member, speaker and advisory committee member for Seattle STD/HIV prevention and training center.

Rafael Padilla, Registered Nurse

Rafael Padilla graduated in 2018 from the University of Washington in Seattle with a Bachelor's in Nursing. He first completed a nurse residency program at a family health clinic where he focused primarily on the management and care of chronic wounds. Rafael joined the Sexual Health Clinic in 2020 to pursue his interests in sexual health and to work more closely with LGBTQ+ communities.

Laura Rishel, Nurse Practitioner

Laura Rishel, MSN, ARNP, is a nurse practitioner at the Sexual Health Clinic at Harborview. Prior to coming to Harborview in January 2018, she worked in primary care at community health clinics in Bellingham and in Maine, where she most enjoyed working in preventive care, sexual and gynecologic health, transgender care and homeless access to health. Her clinical interests include sexual health, transgender care, women's health, and contraception. Laura earned her Master's in Nursing in 2012 from Yale University School of Nursing, and her Bachelor's degrees at the University of Washington.

Thepthara "Nui" Pholsena, Nurse Practitioner

Thepthara "Nui" Pholsena graduated from University of Washington with a Master of Nursing in 2011. Her clinical experience and interests are in chronic diseases, both infectious and non-infectious. For the last three years, she has worked at UW Virology Research Clinic as a research clinician focusing on herpes and vaccine research. She enjoys patient teaching and counseling.

Shannon Winters, Nurse Practitioner

Shannon Winters is a board-certified Adult Nurse Practitioner, credentialed through the American Nurses Credentialing Center, and joined the team at the Sexual Health Clinic in May 2020. After graduating with bachelor's and master's degrees in nursing from the University of Washington in 2009, she spent the first 9 years of her career working in federally-funded family planning clinics in Wyoming and Northern Colorado. During her time in family planning, she enjoyed providing contraceptive care, diagnosing and treating STIs, providing routine gynecologic care, and providing care to patients of all genders.


Link/share our site at www.kingcounty.gov/sexualhealth