Who We Are

What is Internal Medicine?

Internal Medicine doctors are generally seen as “doctors for adults”. Internists are primary care providers just as family practice or “GPs” however we don’t take care of children or manage pregnancy issues. Usually patients come to our office when they feel they have “outgrown their pediatricians”; and because we only deal with adults our training included extra emphasis on some adult issues such as coronary disease, diabetes, infectious disease, endocrine disorders, pulmonary issues and hospital medicine. As a result, we are comfortable seeing a more complicated patient.

What is Family Medicine?

Family Medicine is the medical specialty which provides continuing and comprehensive health care for the individual and family. Family physicians possess unique attitudes, skills, and knowledge which qualify them to provide continuing and comprehensive medical care, health maintenance and preventive services to each member of the family regardless of sex, age or type of problem, be it biological, behavioral, or social. These specialists, because of their background and interactions with the family, are best qualified to serve as each patient’s advocate in all health-related matters, including the appropriate use of consultants, health services, and community resources.

Our Practice

Our cohesive and professional staff have been with us for years and are committed to patient care. Our team treats individual patients like a part of our extended family and their upbeat personalities make patients feel comfortable and at ease. The happy staff at our office genuinely enjoy taking care of patients and work hard to improve their overall health and happiness.

Our long-term staff prides itself on being proactive when it comes to adjusting to changes in the healthcare field. Our transition of care program and chronic care management program are headed by two new nursing staff members and help us provide comprehensive care to our valued patients.

Our family-friendly office setting features comfortable seating for patients of all ages, a first-floor entry, and easy-access parking. With extended hours and the ability for our doctors to take urgent calls from patients on nights and weekends, we are available for patients when they need it most. At Internal Medicine and Family Physicians, you’re more than just a number or a disease. We know our patients on a first-name basis and we do everything necessary to reduce stress while providing the highest level of medical care.

We are members of ACOs (accountable care organizations), which hold us accountable for maintaining the highest level of care.

Our Doctors

Dr. David Allen

Dr. Allen is Board Certified by the American Board of Internal Medicine (ABIM); and a Fellow of the American College of Physicians. Dr. Allen has been providing primary care in Omaha since 2003. He graduated from Kansas City University of Medicine and Biosciences in 1998. He did his residency at the University of Kansas Medical Center in Kansas City. Dr. Allen treats adults with medical issues such as high blood pressure, high cholesterol, diabetes, osteoporosis and depression. Dr. Allen is also certified as a BioTE medical practitioner. He takes a special interest in evaluating and optimizing hormone levels to help treat medical conditions and to maximize a patient’s overall sense of wellness.

Dr. David Sharp

David Sharp, DO, FACOI graduated from Kirksville College of Osteopathic Medicine in 1992. He completed his internship at Michigan State, and residency in Internal Medicine at the University of Nebraska Medical Center. He is board certified in Internal Medicine at the University of Nebraska Medical Center. He is board certified in Internal Medicine and is a Fellow in the American College of Osteopathic Internists. Dr. Sharp has developed and is currently still enrolling patients in his membership based practice, Doctors for Health, with an emphasis on personalized healthcare, advanced lab testing, and increased availability. Dr. Sharp is certified by Age Management Medical Group (AMMG), which focuses on a preventative approach to medicine. Through Dr. Sharp’s certification, he is able to preserve quality of life by optimizing human function through hormone replacement and reducing the aging process caused by chronic disease. Dr. Sharp also treats diagnoses including low back, neck, and hip related pains by using musculoskeletal manipulation, as an alternative or additional treatment plan to pain medications.

Dr. David Keller

Dr. David M. Keller

Dr. Keller is Board Certified in Family Medicine and has been practicing in Omaha for over 20 years. He is a graduate of Creighton Prep, St. Louis University and University of Nebraska Medical Center. He attended St. Francis-Mayo Family Practice Residency in La Crosse, WI. He has extensive experience in the areas of sports medicine, all forms of injuries, wellness, acute and chronic care treatments. He considers it an honor and blessing to work with families towards their optimal health. He and his wife of 26 years have 5 children. His favorite hobbies are dating his wife, playing with his children, bicycling, swimming and kayaking. He especially enjoys helping Nebraska Special Olympics by participating in the Polar Plunge and supporting healthy living with the annual Trek up the Tower event. Dr. Keller would say, “I went into medicine so that I could guide people in the treatment decision process at all stages of life, and that is what I still enjoy about my profession. I appreciate the opportunity to get to know the families I provide medical care for. I focus on preventive health care from birth until natural death.”

Dr. Craig Meier

Craig Meier MD , graduated from the University of Nebraska Medical Center in 1993. He grew up in SW Iowa. He completed his internship and residency in Family Medicine at Madigan Army Medical Center in Tacoma, Washington in 1996. He has been practicing Family Medicine since this time. Initially, he practiced at Fort Riley, Kansas while serving in the US Army until 2000. Since this time, he has been practicing in Elkhorn, NE. He is board certified in Family Medicine and is active in several medical societies. Dr. Meier specializes in care of all ages from infants to the elderly. He has special interests in Preventive Care and in Sports Medicine. He has been a sideline physician in the Elkhorn area for many years. Dr. Meier is a preceptor for medical students and enjoys volunteering his time teaching the next generation of doctors. Dr. Meier also is a certified BioTE Hormone replacement provider since January of 2015.

Dr. Maen Haddadin

Dr. Maen Haddadin has been a Family Doctor since 1998. After graduation from Jordan University and finishing his medical training through the Creighton University Residency Program, he started his primary care career in Corning Iowa. He stayed in Corning for 18 years,then moved to Omaha, Nebraska to join Internal Medicine and Family Physician in February of 2020. Dr Haddadin brings extensive medical training and experience within the family medicine field, especially brings passion about preventative healthcare and management of chronic health disorders such as diabetes, sleep apnea, hypertension and strokes and among many others. Dr Haddadin is committed to personalized care for all and will take the time to listen to his patient’s concerns while giving advice and support through all forms of treatment. He believes that his role for his patients is to be a health advocate by managing and treating, thus improving there health so they can live a long and productive life with their loved ones. Dr Haddadin considers his patients as family and friends, and he would be honored to be your physician. Dr Haddadin along with his wife and four boys are very active within their church. In his spare time he enjoys playing basketball and staying active.

Our Staff

Katie Horner, PA-C, MPAS

Katie Horner is a highly experienced Physician Assistant/Associate with a passion for providing comprehensive care to patients. With a Master's degree from UNMC in 2000 and NCCPA certification, she has been practicing in primary care since 2001 and has been an invaluable member of the Internal Medicine and Family Physicians team since its opening in 2007.

Katie's dedication to her patients goes beyond simply treating acute and chronic conditions. She firmly believes in empowering her patients to live well and longer through patient education and preventative healthcare strategies. Her expertise extends to hormonal care for both men and women, as she is BioTe trained and certified.

Known for her exceptional listening skills, Katie takes the time to understand her patients' needs and concerns. She approaches each case with empathy and compassion, ensuring that her patients feel heard and valued.

Outside of her profession, Katie enjoys a fulfilling personal life. She finds joy in time with her family, singing at local venues, reading and exercising. Additionally, she actively volunteers in her community.

You can expect Exemplary medical care combined with warmth and genuine concern with Katie Horner as your healthcare provider.

Stacy Niemi MSN, APRN, BC

Stacy received her Masters of Science in Nursing from the University of Nebraska Medical Center with an emphasis in family practice. She also holds a Bachelor in Corporate Fitness and nutrition as well as an Associate Degree as a physical therapy assistant.

Stacy has been practicing Bio-identical Hormone therapy for over a decade and is certified by both Worldlink Medical and BioTe methodologies. She has is certified by the AOAPRM in prolotherapy for regenerative medicine for pain therapy. Stacy also believes once you start feeling good on the inside it converts to how you look on the outside and is certified as an expert injector for various aesthetic products.

Stacy’s emphasis in on preventative medicine and wellness and has enjoyed practicing this in both her home life and her career for over 25 years. She also enjoys treating all aspects of healthcare from routine annual exams and acute injuries to chronic disease states.

Stacy is married, has 3 sons and enjoys most all outside summer activities and in the fall it’s all about football!

Leanne Galvan, DNP, APRN, NP-C

Leanne Galvan, DNP, APRN, NP-C

Leanne received her Doctorate of Nursing Practice from Nebraska Methodist College in 2018. She also obtained a bachelor’s degree in Education from the University of Nebraska-Omaha. She is board certified by The American Association of Nurse Practitioners and cares for patients with routine and complex medical problems. Leanne is trained in the BioTe method of bioidentical hormones and especially enjoys educating about prevention and wellness.

Abigail Lanik, PA-C, MPAS

Abigail received her Masters of Physician Assistant Studies from the University of Nebraska Medical Center in 2016. She also received a Bachelor’s degree in Biology from the University of Nebraska-Lincoln. She is NCCPA Board Certified. Abigail has been focused on Internal Medicine since graduation. Her special interests include preventative medicine and management of chronic diseases. She is from Omaha, NE and enjoys traveling, hiking, and running.

Jennifer Stodden, PA-C

Jennifer, a native of Fremont, Nebraska, received her Master’s in Physician Assistant studies from the University of Iowa in 1997. She has been working at a private family practice clinic in Onawa, Iowa since that time. She is board certified by NCCPA. She enjoys taking care of patients of all ages, but especially enjoys geriatrics. She lives in Elkhorn with her two children, Alex and Sydney. She has been employed part time at Internal Medicine and Family Physicians since 2016.

Catie McQuistan, PA-C

Catherine (Catie) McQuistan is a board-certified physician assistant who graduated from Midwestern University in Downers Grove, IL with a Masters of Physician Studies in 2016. She worked in the Chicago suburbs before moving back to Omaha to be closer to family and continue her career. Catie has worked in the primary care setting since graduation. She has a special interest in both acute and preventative care, mental health and patient education. Catie believes it is important to spend time with patients and listen to their concerns, questions and goals in order to come up with the best treatment plan for them. She enjoys educating patients and answering any questions they might have during their visit. Catie and her husband welcomed their first daughter in 2023 and in her spare time she enjoys spending time with her family, reading, traveling, golfing and staying active.