Dr. Steven Elsesser is a primary care provider at our Boston (Kenmore) location. He earned a BA in clinical psychology from Tufts University and began his career in HIV research, shaping his commitment to HIV primary care. He completed a family medicine residency at the University of Pennsylvania with a focus on HIV primary care, LGBTQIA+ care, and the care of complex chronic illness.

“Primary care works best as a partnership. I strive to meet patients where they are, make sense of complex health information together, and support their goals with evidence-based guidance that feels personal and affirming.

Tyler Gillingham is a nurse practitioner and primary care provider at our Boston (Kenmore) location. He completed his training at MGH Institute of Health Professionals in 2020 and is board-certified through the American Nurses Credentialing Center. I am also a certified HIV specialist with the American Academy of HIV Medicine. My practice interests include LGBTQIA+, HIV primary care, and preventative primary care. Tyler joined Atrius Health in 2023, having previously worked at Fenway Health.

"My philosophy in caring for my community is centered on open, patient-led conversations to create a comfortable and collaborative environment. I am passionate about preventive care, education, and a safe space. I strive to empower patients to take charge of their health and support them in a holistic and non-stigmatized environment. My main priority is for any patient to leave a visit feeling heard. I am very excited about what the Pride + Care program at Atrius has to offer our community."

Ning Nie is a nurse practitioner at our Boston (Copley) location. He completed training at MGH Institute of Health Professionals in 2023 and is board certified through the American Academy of Nurse Practitioners. He joined Atrius Health in 2026. His clinical interests include LGBTQIA+ health, gender-affirming care, HIV prevention, and trauma-informed care.

"I believe the patient is the conductor of their health care and my role is to work collaboratively with each patient to achieve optimal health and well-being. I strive to create an environment for my patients that feels safe, affirming, non-stigmatizing, and non-judgmental."

Roberto Mastroianni is a nurse practitioner and primary care provider at our Peabody location. He completed his training at Simmons University and is board-certified through the American Nurses Credentialing Center. Roberto joined Atrius Health in 2023, having previously worked at East Boston Neighborhood Health Center. He is fluent in both English and Spanish.

"As a member of the LGBTQIA+ community, I am deeply committed to ensuring that individuals within our community receive high-quality, affirming primary care. With 15 years of dedicated experience in caring for marginalized populations and actively combating health disparities, being a part of Pride+ Care is a significant step in my mission to provide inclusive and compassionate healthcare for LGBTQIA+ individuals.

My philosophy of care is rooted in understanding and addressing the unique healthcare needs of LGBTQIA+ patients. I believe in creating a healthcare experience where every patient feels seen, heard, and valued. It is essential to recognize the diverse experiences and challenges that LGBTQIA+ individuals face, including those related to mental health, chronic disease management, and preventive care. By fostering open communication and building trust, I aim to empower my patients to take an active role in their health and well-being.

When patients come to see me, they can expect a welcoming and supportive atmosphere. I prioritize patient-centered care, ensuring that each individual's specific needs and concerns are addressed with sensitivity and expertise. My goal is to create a safe, supportive space where all individuals feel comfortable discussing their health concerns and receive the care they need. I am excited to partner with my patients in fostering a healthier, more equitable future for the LGBTQIA+ community."

Emily Waldon is a physician assistant at our Cambridge location. As a member of the LGBTQIA+ community, she understands the importance of people in her community being seen and heard, and this is especially true in a healthcare setting. She is excited to bring the pride+ services to the forefront of healthcare for Atrius patients.

"My philosophy in caring for members of our community is that each person is unique and has healthcare needs that are unique to them. I think it is important to understand my patients as a whole person in order to provide the best comprehensive care for them.

When a patient comes to see me, they can expect a personalized experience where we collaborate on what their health care goals are and work together to achieve their optimal health."

As a member of the LGBTQIA+ community myself, I feel driven to provide high quality care for patients of all gender identities and sexual orientations. As this community has far too long been stigmatized and mistreated by the medical community, I am thrilled to contribute to changing this cycle as part of the Pride+ program at Atrius Health.

A gynecologic exam can often be found to be invasive, at best, or traumatic, at worst. However, I endeavor to ensure all patients feel as safe and comfortable as possible in my office. Some of the ways I seek to accomplish this, especially with my LGBTQIA+ patients, are to defer the exam until the patient feels ready and offer medication to help with anxiety and/or pain if needed.

When patients come to see me, they can expect to find a provider focused on meeting their individual needs in an open, empathetic and evidence-based manner, free of unnecessary restrictions or gatekeeping that has previously plagued this community.

Dr. Muscanell cares for patients at our Quincy Hancock Street and Boston (Copley) loctions.

Please speak with your Pride+ Care provider to be referred to Dr. Muscanell.

Sarah Hundley, PsyD is a clinical psychologist in Behavioral Health, with a specialty in trauma and a focus on early childhood abuse and neglect. She works with both adults and children and is involved in gender affirming care, including writing letters in support of gender affirming surgery and facilitating the Trans Identified Support Group.

"I am a member of the LGBTQIA+ community and am passionate about supporting people in discovering and living as their authentic selves. I approach my work through an intersectional, trauma informed lens—recognizing how early experiences, overlapping identities, and systems of oppression shape mental health and access to care. I am deeply aware of the challenges marginalized communities face when navigating the healthcare system and emphasize collaboration, curiosity, and respect for lived experience."

Dr. Hundley cares for patients at our Chelmsford and Medford locations.

Please speak with your Pride+ Care provider to be referred to Dr. Hundley.

River Armstrong completed their Master’s of Public Health at Boston University with a focus in community program development and LGBTQ+ health. They are passionate about community collaboration, program development, and reflective evaluation as tools to understand and address systemic barriers that impede accessible and equitable care. River brings their experience supporting the healthcare and social needs of transgender and gender diverse populations at Boston Medical Center’s GenderCare Center and the Massachusetts Transgender Political Coalition.

“As the Pride+ Care Program Manager, my goal is to bridge the gaps between patients, clinicians, and our Atrius organization to create a more affirming and accessible healthcare system. I believe transparent communication and listening to our patients is key to a successful program. Whether it’s answering your Pride+ Care questions or connecting you to the right department, I am here to support you in having a great experience with our program.”

Bhavana Khanna completed her Master’s in Public Health at Johns Hopkins University in Health Education and Health Communication. She is passionate about ensuring quality and informative care for LGBTQ+ patients by enhancing patient-provider communication. Bhavana brings combined experience in HIV prevention, sexual health education, and interpersonal communication from her work with the Centers for Disease Control and Prevention and Maryland Department of Health.

“I am excited to start my role as the Pride+ Care Facilitator and work together with an incredible team to provide compassionate and inclusive care to patients who need it the most. My role involves providing insurance, financial, housing, and other resources and information to patients in the Pride+ Care program, while also working with clinicians to coordinate quality care and health service. This program has great potential to improve how Atrius health approaches LGBTQ+ care, as well as to pave the way for other programs."