Your Expert Doctors in Concord, CA

Meet our father and daughter team making a MAJOR difference in our community.

Meet Fred Von Stieff, M.D., M.B.A.

Pioneering healthy changes for the people of Concord, Martinez, and the Bay Area.

doctors in concord ca - Dr. Von Stieff with a patient and in a headshot

“We are most dedicated to your healthcare.”

Dr. Fred Von Stieff is not only Dr. Carpenter’s father; he is viewed as a father figure by the majority of our team and patients. He has a personal interest in all his patients and ensures their care is of paramount importance. He is a true leader in the medical industry and is dedicated to improving the health of everyone he meets.

Dr. Von Stieff has retired from the Family Practice, but he still works at the Center for Recovery at John Muir in Concord. He enjoys a good family life and brings that joy and happiness to his office. His very positive and forward-thinking traits are truly valued by each of his patients.

Outside of the office, he loves to be active by going hiking and sailing, enjoys gardening, horseback riding, and taking care of his dogs.


  • Medical Director of the Shell Oil Refinery
  • Industrial Medicine Physician
  • Over 30 years working with the Internal Medicine Group
  • Joined the John Muir Hospital in 1979 in the Intensive Care Unit
  • Started a practice at the Center for Recovery – John Muir Health’s Chemical Dependency Unit.
  • Years of experience working in Addiction Medicine, Family Practice, and Industrial Medicine


  • Graduate of the University of California
  • Graduate of the Irvine School of Medicine
  • Three year Family Practice residency at the University of California, Davis

Qualifications/ Memberships

  • American Society of Addiction Medicine
  • California Society of Addiction Medicine
  • American Board of Addiction Medicine

“Dr. Von Stieff was genuinely involved with every patient – tough thing to do with a ward full of sick and sometimes difficult people.”

– Actual Von Stieff Patient

Meet Kristi Carpenter, D.O., M.B.A.

Using innovative care for the benefit of patients of all ages.

doctors in concord ca - Dr. Carpenter in a headshot and with her little girl

“Laughter is the best medicine.”

Dr. Carpenter is a board-certified family practice physician who has an undying passion for helping people of all backgrounds and circumstances. She enjoys the practice of family medicine because it is a privilege to take care of an entire family and to always put her patients and their preventative medicine first.

She thrives when working with her friendly, fun team because they all share the same drive and determination to better people’s lives. You can find Dr. Carpenter working 2 days a week – Tuesdays at Concord and Thursdays at Martinez.

In her free time, Dr. Carpenter spends time with her four children and her husband who is also in the medical field. She enjoys the outdoors, gardening, barbecuing, and watching her children play sports.


  • Completed an internship and residency through the University of California
  • Davis residency network at San Joaquin General Hospital
  • Chief Resident at San Joaquin General Hospital
  • Joined her father’s practice in 2016


  • Earned her Bachelor of Science degree in Biotechnology and with a minor in Sociology from the University of California, Davis
  • MBA from St. Mary’s College
  • Doctorate of Osteopathic Medicine degree from Touro University
  • Trained extensively on management of chronic conditions, including diabetes, hypertension, and congestive heart failure.

Qualifications/ Memberships

  • Board-certified Family Practice Physician
  • Trained in Pediatrics and Women’s Health
  • Trained in Occupational and Addiction Medicine
  • American Society of Addiction Medicine

Meet Our Team

Dr. Rick Carpenter
  • Received his Medicinal Chemistry PH.D. in 2008.
  • Graduated from Touro University of California Medical School in 2017.
  • Completed his medical residency at Valley Family Medicine Residency Program.
NP Alison Sloan
  • Working Monday – Friday at our Concord office
NP Aura Sanchez-Mundi
  • Working Wednesdays at our Concord office
Doctors in Concord CA - Collage of the office and team

How Can We Help You?