The providers at East Valley Internal Medicine strive to provide compassionate, comprehensive care for all patients. Our well-trained group of providers has a combined 120 years of experience. All provide women’s and men’s health care. Some have specific areas of expertise.

Mark Walmer, MD

 specialty: Internal medicine and Addiction medicine

Dr. Mark Walmer is board certified in internal medicine. He is the founder of East Valley Internal Medicine and has been practicing since 1984. He specializes in addiction medicine, preventative medicine, hypertension, hypercholesterolemia, and diabetes. Dr. Walmer earned his medical degree from the Medical University of South Carolina in Charleston, South Carolina. He completed his residency at St. Joseph’s Hospital and Medical Center in Phoenix, Arizona. He is the president and medical director of East Valley Internal Medicine.

Armando Rodriguez-Asbun, MD

specialty: Internal Medicine

Dr. Armando Rodriguez-Asbun is board certified in internal medicine and has been practicing since 1996. Dr. Rodriguez-Asbun earned his medical degree from Escuela Nac De Estudios Profls in Tialnepantla, Mexico. He completed an internship and residency at Maricopa Medical Center in Phoenix, Arizona.  Dr. Rodriguez-Asbun also speaks Spanish and has been commended for his care of the diabetic community.

Christina Zimmerman, MSN, NP-C

specialty: Women’s Health, Preventative Medicine, Longevity Care

Christina is a board-certified nurse practitioner and has been practicing medicine sine 2009. She completed her undergraduate studies in nursing and earned her master’s degree at the University of Arizona in Tucson, Arizona.

When Christina isn’t at the office treating patients, she enjoys spending time with her young son and staying physically fit.

Stephanie Martinez, ACNP-BC

specialty: Acute Care, Women’s Health, Preventative Medicine, Longevity Care

Stephanie is a board-certified nurse practitioner and has been practicing medicine since 2010. She completed her undergraduate studies in nursing and earned her master’s degree at Grand Canyon University in Phoenix, Arizona.

Stephanie’s special interests include hiking, running, reading and spending time with her family.

Robert Halligan, MD

specialty: Addiction Medicine
Dr. Robert Halligan is board certified in internal medicine and addiction medicine has been practicing since 1994. Dr. Robert Halligan earned his medical degree from Creighton University School of Medicine in Omaha, Nebraska. He completed an internship and residency at Good Samaritan Regional Medical Center in Phoenix, Arizona.

Dr. Halligan enjoys spending time with his family and many outdoor activities such as running, cycling, golfing and skiing.

Boris Schwartz, NP

specialty: Pain Medicine

New Provider Coming Soon

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