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Our Providers

The Doctors of Foxhall Medicine

Foxhall Medicine was designed to be a practice where specialists would gather to provide personalized care for their patients. The doctors who comprise our staff have been professionally trained and have years of experience working with, and healing, patients.

Each doctor’s approach to their specialty differs, but the common thread that runs throughout Foxhall Medicine is the dedication we give to each patient, along with using our medical knowledge and resources to provide accurate diagnosis.

Joshua S. Yamamoto, M.D., F.A.C.C.

Dr. Joshua S. YamamotoDr. Joshua S. Yamamoto was born in Washington, D.C. He graduated with a degree in physics from Princeton University, and subsequently worked as a paramedic for the Alexandria City Fire Department before attending Dartmouth Medical School. He trained on the Osler Medical Service at The Johns Hopkins Hospital, and then completed cardiology training at the National Naval Medical Center and Georgetown University. He was the cardiology consultant to the US Congress, Director of Cardiac Imaging, and held a faculty appointment at the Uniformed Services University. In 2005, he was lent to the Army and served in Kuwait as the theater cardiologist for the ongoing wars in Iraq and Afghanistan. Upon his return, he dutifully followed orders and joined his wife in private practice.

Dr. Yamamoto provides only cardiology services at Foxhall Medicine (he is not available for primary care services).

Kristin E. Thomas, M.D.

Dr. Kristin E. ThomasDr. Kristin Thomas graduated with honors from the University of Michigan in 1990 and then completed her medical degree at Michigan in 1994. She finished residency training at Johns Hopkins Hospital in 1997 and then was appointed one of Hopkins first hospitalists in 1997, serving for one year in this faculty position. In 1998 she served a year on faculty at Hopkins as Chief Resident. She completed six months of fellowship training at Hopkins in Rheumatology in 1999 prior to moving to Washington DC where she joined Foxhall Internists, P.C., in December 1999.

Dr. Thomas was a partner with Foxhall Internists, P.C. until starting Foxhall Medicine, PL.L.C. with her husband in 2013. She is a Board Certified Internist.

Dr. Thomas enjoys seeing patients of all ages and has a diverse patient population. She manages both acute and chronic medical problems and particularly appreciates patients with diagnostic dilemmas and complicated medical issues. She is on the clinical staff at Georgetown University Hospital and Sibley Memorial Hospital. She and her husband reside with their family in Maryland.

Vianca Valis

Vianca ValisVianca Valis Vianca was born in Silver Spring, MD and attended Wootton High School where she took her first nutrition class and “fell in love with”. She holds a Bachelors of Science in Community Health from the School of Public Health at The University of Maryland, where she graduated in December 2015.

In 2016 she earned a Health Education Specialist Certification through The National Commission for Health Education Credentialing, Inc. She then worked as a Health and Wellness coach focusing on weight loss and weight maintenance. She then went on to manage a karate studio and in March of 2019 she earned her Health Coach certification through The American Council on Exercise.

Vianca began practicing karate at the age of 7, in the style of tang soo do and has obtained her second degree black belt. She began teaching karate when at the age of 19 and did so throughout college, working and training under Mr. Ricky.

In her free time she likes to go to the gym, take barre classes, practice karate, go to concerts and spend time with friends/family. Aside from nutrition and karate, her passion is traveling. She makes it a priority to travel to at least one new place each year.

Vianca currently lives in Silver Spring, MD.