Office Hours

Monday through Friday 8 a.m. to 5 p.m. | Phones open at 8:30 a.m. | Closed on Saturday and Sunday

Emergency/After-Hours Contact

After hours, please call (913) 541-3340 and our answering service will inform you how to reach a physician on call. Please be considerate of the time of day you call for non-urgent questions.

Find Us

Quivira Internal Medicine
10601 Quivira Rd Ste 200
Overland Park, KS 66215
(913) 541-3340
Fax: (913) 492-7857
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Thomas Barnett, MD
Dr. Barnett was born and raised in the Kansas City area. He attended the University of Missouri at Kansas City Medical School and was the first graduate from the six-year combined degree program. From there he attended St. Luke's Hospital in Kansas City, completing both his internal medicine residency and his gastroenterology fellowship. On completion of his GI fellowship, he received a scholoarship to study liver diseases at the Royal Free Hospital in London, England. Dr. Barnett has been practicing medicine in the Kansas City area for more than 27 years. He is board-certified in both internal medicine and gastroenterology. He feels being active in clinical research keeps his clinical skills and medical knowledge current and up to date. Dr. Barnett has served on numerous hospital committees and as president of the medical staff at Overland Park Regional Medical Center.

Martin Buckman, MD
Dr. Buckman was born and raised in North Kansas City, Missouri where he participated in football, basketball and track. He received his undergraduate degree from Washington University in St. Louis before teaching high school in Independence, Missouri. He subsequently graduated from the University of Missouri-Columbia School of Medicine and completed his residency in Internal Medicine at St. Luke's Hospital. He worked as an individual private practitioner at Overland Park Regional Medical Center until joining Quivira Internal Medicine in June 2008. He describes his years in private practice as "an opportunity to serve 2,000 of my closest friends." Dr. Buckman is board-certified in internal medicine with a focus on preventative medicine.

James Cheray, MD
Dr. Cheray attended pharmacy school at Creighton University prior to completing medical school training at the University of Kansas. He completed his internship and residency training at the University of Nebraska Medical Center before returning to native Overland Park, to join the Kenyon Clinic. Dr. Cheray is on the medical staff at Overland Park Regional and Mid-America Rehabilitation Hospital. He has served as department chair of internal medicine and has been the physician director of the Skin and Wound Management Team. He has been a delegate to the Kansas Medical Society. He is board-certified by the American Board of Internal Medicine. Dr. Cheray's medical interests focus on providing preventative care to his patients. He specializes in screening procedures including exercise treadmill stress testing and bone density exams.

Michelle Lester, MD
Dr. Michelle R. Lester joined the medical practice of Quivira Internal Medicine and is now part of the active medical staff at Overland Park Regional Medical Center. Dr. Lester, a major in the US Air Force, was medical director at Lackland Air Force Base in San Antonio, Texas. Dr. Lester joins the long tradition of providing accessible, quality healthcare established by Quivira Internal Medicine: specializing in the prevention and treatment of adult diseases. Dr. Lester is board-certified in internal medicine. She received her medical degree from the University of Kansas School of Medicine and completed her residency in internal medicine at Wilford Hall Medical Center in San Antonio.

John Mallory, MD
Dr. Mallory began his medical practice in the Kansas City area after completing his military service at Irwin Army Hospital. He is a graduate of the University of Missouri-Columbia. His undergraduate work was completed at Graceland College, Lamoni, Iowa and at the University of Missouri, Kansas City. His internship and residency were completed at Ohio State University. He is certified in both internal medicine and geriatric medicine. Dr. Mallory is a fellow in the American College of Physicians and past president of the Wyandotte County Medical Society and the Kansas City Society of Internal Medicine. Dr. Mallory has served as principal investigator and as a sub-investigator on several pharmaceutical research trials.

Lawrence Riffel, MD
Dr. Riffel is a Kansas native and has practiced internal medicine in Overland Park since 1981. He received his BS from Kansas State University and his MD from the University of Kansas. He completed a three-year internal medicine residency program at the University of Iowa before returning to Overland Park to practice. He is active in the Johnson County Medical Society and has served as its president. He has served on the hospital Board of Governors, executive committees, Chairman of the Department of Medicine, and as president of the medical staff of Overland Park Regional. Dr. Riffel has served as a principal investigator and as a sub-investigator on several pharmaceutical research trials. He is board-certified in internal medicine and is a fellow in the American College of Physicians.

Vijaya Samuel, MD
Dr. Vijaya Samuel is an internist who went to medical school at the University of Madras, India. Prior to residency, Dr. Samuel did a year of research at Mt. Sinai Hospital, New York. She did her post-graduation at University of Syracuse and at the University of Nevada School of Medicine. Dr. Samuel was then an associate professor at the University Medical Center in Nevada and subsequently moved to ambulatory care at the University. Dr. Samuel was a faculty member at the University of Rochester, New York for three years. She is board-certified in internal medicine and is a fellow in the American College of Physicians. She has been practicing in Kansas City since 2001 at Quivira Internal Medicine.

George Stamos, MD
Dr. Stamos grew up in the small town of Tipton, Iowa. He enjoyed growing up in a small town and was a four-sport letterman in high school. He attended the University of Iowa and graduated from the University of Iowa School of Medicine. He did a year internship in Johnstown, Pennsylvania and completed his residency in internal medicine at St. Luke's Hospital in Kansas City. He has been practicing medicine in the Kansas City area for more than 35 years. Dr. Stamos is board-certified in internal medicine and is a fellow of the American College of Physicians. He has been instrumental in the development of the Overland Park Regional Hospital Campus and also in the development of Quivira Internal Medicine. His practice is focused on preventative health care issues including hypertension, hyperlipidemia, obesity and diabetes.

Shazia Walijan-Munir, MD
Dr. Shazia Walijan-Munir has recently moved to Kansas City to be with her family after being in Pittsfield, Massachusetts where she practiced Internal Medicine at Community Health Programs Incorporated. Dr. Walijan-Munir graduated from DOW University of Health Sciences, Pakistan where she was a primary care physician for three years in Karachi, Pakistan. Dr Shazia Walijan-Munir then came to the states to pursue further education and training. She did a three-year residency in Internal Medicine at Berkshire Medical Center, University of Massachusetts where she was chief resident for a year and had active involvement in teaching of internal medicine residents and students from University of Massachusetts. She is American board certified in Internal Medicine and is also a fellow in American College of Physicians. Her primary interests in medicine are preventative health care issues including hypertension, hyperlipidemia, obesity, diabetes, and Women's health.

Lori Knudtson, MSN, ARNP, FNP-C, CDE
Lori Knudtson received her bachelor's degree in nursing from Baker University. She graduated from the University of Kansas with a master's degree in nursing. Lori is a board-certified family nurse practitioner and is also a certified Diabetes Educator. Lori manages patients with acute health problems and works in collaboration with the Quivira Internal Medicine physicians in the management of chronic health conditions. She has a particular interest in diabetes education and management.

Debra Morris, MSN, APRN-C
Debra received a bachelor’s degree in nursing from Washburn University. She graduated from the University of Kansas with a master’s degree in nursing. Debra is a board certified adult/geriatric nurse practitioner. She works in collaboration with the Quivira Internal Medicine physicians. Debra has a special interest working with geriatric patients as well as managing chronic health conditions. Debra works full time Monday through Friday.

This practice accepts ALL major health insurance plans in the Kansas City area.

Forms of payment*:

• Cash
• Discover
• MasterCard
• Personal Check
• Visa

• Flu.gov
• Go Red for Women
• American Academy of Family Physicians
• American College of Physicians, Internal Medicine
• American Medical Association
• American Osteopathic Association
• Centers for Disease Control and Prevention

Reduce your wait time! Download, print, and bring the completed forms with you for your upcoming appointment.

• Medical History Form
• Patient Registration Form | Patient Registration Form (Spanish)
• Consent to Treatment Form | Consent to Treatment Form (Spanish)
• Disclosure Authorization Form
• Medicare Patients only: Medicare Secondary Questionnaire | Medicare Secondary Questionnaire (Spanish)
• Medicare Health Risk Assessment Form (for physical/wellness exam only)
• Request for Medical Records