Call us anytime (714) 547-5375

Meet Our Dedicated Team

Cornerstone prides itself on being a family-run, community-focused business. Understanding the importance of community means we truly understand the importance of quality staff, for these people form the heart, the cornerstone of our community. As such, we aim to offer outstanding employee benefits to our staff, as we know we get back what we put in.

Cornerstone is proud to boast a team of the most highly skilled experts in the Substance Use and addictions field. Our staff are all fully trained in treating chemical dependency and related addictions. We also employ many people with experience of substance use disorders or addiction themselves, as we understand that those who have been through the recovery process are well equipped to help another recovering addict get to where they are. We are exceptionally proud of our 90 employees and affiliates.

Over the years we have attracted some of the most senior members of Orange County’s medical and psychological team. Many wanting to work for us because of our exceptional working conditions, camaraderie and sense of community.

Michael Stone

Michael Stone, MD, FAAFP, ABAM, FASAM

Founder and Chief Medical Officer
Dr. Stone founded Cornerstone of Southern California in 1984 when he recognized that many addicts who needed help could not afford prolonged hospital stays. Being well versed in the treatment of addiction, he also understood that the sterile conditions of a hospital setting were so far removed from the addict’s normal life, that they were not conducive to long lasting recovery. Deciding to rectify this he set up Cornerstone of California. A place he could offer addicts seeking recovery a safe, non judgmental space where they could learn about the disease of addiction, understand their triggers, look deeper, through various empirically tested therapeutic methods, at the core reasons for their illness, while living amongst other people in a community where they could relearn basic living skills and how to socially interact. Dr. Stone has treated over 80,000 addicts and their families’ since 1969. He is well known and respected in the professional community. Dr. Stone has refused to allow Cornerstone, or himself, be pigeon holed or type cast. He has treated individuals from all walks of life. His priority is setting the individual on the path to successful, long lasting recovery, regardless of whether they are a celebrity or homeless. Dr. Stone graduated from Sheffield University Medical School, England in 1967. In 1969 he opened and directed the first in-hospital drug and alcohol treatment center in Canada. He then became Medical Director of Care Unit Hospital, Orange County, a famous psychiatric hospital. During his employment at Care Unit, the prevalence of alcoholism and drug addiction increased exponentially. Dr. Stone’s experience and ability were highly esteemed and he was asked by Betty Ford if he could, along with his team, train the Directors at the Betty Ford Center by Mrs. Betty Ford. Dr. Stone has committed himself to help people with addictive diseases for over 50 years. He has had extensive training in the field of addiction and is board certified in family medicine, board certified by the American Board of Addiction Medicine and a diplomat of the American Academy of Pain Management. Personal Life: Dr. Stone has been married since 1967. He is extremely proud of his three adult children who work full-time at Cornerstone. He enjoys the beach, loves dogs, and reads science fiction novels in his free time. He is a doting grandfather to five grandchildren.

Lin Long, BC-FNP

Family Nurse Practitioner

Jeanette Ponce, MD


Dr. Ponce is Board-certified in Family Practice with a solid knowledge base and experience with addiction issues and medicine. She has extensive experience providing integrated primary care for patients with mental health and alcohol and drug-related issues serving as a family practice physician, internal medicine hospitalist, internist, and health educator during her career.  

Dr. Ponce earned her Medical Degree from UCLA and her Bachelor of Science in Biochemistry and Cell Biology from the University of California at San Diego.

Amal Bolis Tanagho, MD

Amal Bolis Tanagho, MD

Consulting Psychiatrist

Phil Kosanovich, MBA

Chief Executive Officer

Phil has a senior leadership profile that spans from entrepreneurial ventures to global corporations. His experience includes consulting, operational, and executive level roles in the behavioral health and addiction treatment industries that include co-founding and growing two residential and outpatient treatment centers.

Phil is an inclusive and transformational leader with a reputation for building strong client/patient centered teams focused on clinical excellence. He has an extensive record of success in leading companies through transitional periods of growth and creating and maintaining strong external partner relationships.

Phil’s expanded healthcare industry experience was with Landauer, where he started two subsidiary companies and led company operations in Australia and China. Prior to his 30 years in healthcare industries, Phil was president of human resource and financial services related subsidiaries of Travelers, Equitable, Lincoln Financial Group and Chicago Title & Trust. He has served on the executive board and in multiple leadership roles of a global human resources trade organization and elected into that industry groups Hall of Leaders.

Phil has served on the boards of several healthcare related charities and is the Chair of the Community Relations Commission in his hometown. Phil earned an MBA from DePaul University and a Bachelor of Science in Business Administration from Valparaiso University. He is in long term recovery.

Jessica Stone

Co-founder Executive Assistant

Since Cornerstone’s inception, Jessica Stone has been an integral component of the family business. Co-founding it in 1984 with Michael, she has tirelessly dedicated her life to the improvement of recovery outcomes for thousands of addicts.

Personal life:

Born in India, she grew up in the UK where she met and married Dr. Stone in 1967.

Jessica is extremely proud of her three children, Simon, Samantha and Tim, who have also dedicated their lives to Cornerstone and the treatment of addictive disorders. Like her husband, she is a doting grandmother of her five grandchildren.

Samantha Stone, BA


She started in the Business office sending out insurance claims and collections. After that she moved to Admissions and Intake. She has spent most of her career in Intake/Admissions talking to potential patients and families about the programs at Cornerstone and what to expect. From Intake she moved into Management with becoming the Senior Vice President then President in 2019.

Personal Life:

Sam has love for all animals especially dogs and cats. She loves hiking, road-biking, movies, theater, traveling, and different cuisines. She is currently assisting in helping Cornerstone start an LGBT (short for LGBTQIA2+) program.

Simon A. Stone, BA

Senior Vice President, Safety Officer, Corporate Business Development and Court Liason

Along side his duties as Senior Vice President of the company, Simon acts as Cornerstone’s Safety Officer. His main role addresses continuous quality improvement and management of Cornerstone estate. He ensures that the property is continuously well managed and that the facilities are up-to-date, comfortable and safe for our many clients, staff, and visitors.

Simon also assists in our Alternative Sentencing Program, where he passionately advocates for treatment in lieu of jail time in conjunction with criminal defence attorneys, public defenders, district attorneys, judges and commissioners.

Personal Life:

He enjoys surfing, traveling in his “sports mobile” and raising four beautiful children, four turtles, five fish, one dog, one cat, and one hamster, always with the constant support of his wife, Kari.

Timothy Stone, BA

Senior Vice President

Tim Stone has been part of the Cornerstone Team since 1999. He began his career assisting with the upkeep of the Recovery Residences that he now oversees. Tim’s responsibilities include ensuring that Cornerstone’s Recovery Residences are following the California DHCS, Joint Commission and CCAPP regulations at all times. Tim is also responsible for Cornerstones IT, SEO and overall on-line presence, working as the company liaison with our external expert partners in these areas. Tim is also responsible for our ‘Environment of Care’ team, which is accountable for all the on-going maintenance, repair, improvement and housekeeping needs of the company.

Personal Life:

Tim enjoys surfing, reading a good book and playing guitar. He was the Lead Singer/Songwriter for the music group The Goodkind (for those interested, find them on Spotify).

Tami K. Campbell, CADC-CAS

Director of Operations

Lesley Nolen, RADT

Marketing and Outreach

Robert C. Griffin

Human Resources

Aryan Monroe, MA, LMFT, CS

Clinical Director

Monnaye Bernal, ASW


William Dexter, MA, AMFT


Christine Graves


Edith Sandoval


David Schornack

Case Manager/Therapist

Dane Jones, CADC I

Outpatient Program Manager

Diane Shaw, CADC II

Lead Case Manager

Maria Carter, CADC II

Case Manager

Crystal Melms, CADC II, CCDS

Case Manager

Montana Dellinger, BA, RADT

Case Manager
Victoria Scott

Victoria Scott, BSHS, MS, LAADC

Case Manager

Roberto Hernandez

Case Manager

Samuel David Michael, RADT

Counselor Tech

Lietta Brutsche

Case Manager

Marlys Wood, MS AMFT, MT BC

Music Therapist

Marlys Woods is a board-certified music therapist who has extensive experience supplying music therapy to substance abuse facilities. She has performed and taught music her entire life.

Marlys graduated from Chapman University in 2011 with a degree in music therapy and a minor in psychology, and she graduated from Vanguard University with an MS in clinical psychology. Marlys is in the process of becoming a marriage and family therapist and enjoys using her knowledge of relationships, people and music to help those who are struggling with addiction.

Marlys brings a variety of interventions such as active music making, songwriting, and lyric analysis, as well as relaxation techniques and art paired with music to her sessions. Marlys has successfully used these interventions to facilitate Cornerstone clients’ finding healthy coping skills as they move forward on their journey of sobriety.

Casey M, BA, E-RYT200

Yoga Instructor

Anya Chernitskaya, BSHS, CADC-CAS

Senior Admissions Group Manager

Mark Ballard, CADC I

Admissions and Quality Assurance Manager

Mary Fritz, CADC-CAS

Senior Admissions Counselor

Tayler Young, BA, RADT

Admissions Counselor

Roberto Palacios, CADC I

Admissions Counselor

Natalie Plappert

Admissions Counselor

Sarah Rahrouh, MS, RADT

Admissions Counselor

April Arentz, LVN, CADC, BSP

Administrative Coordinator

Sean Avilla, LVN

Wellness Coordinator

Oumaima Shilleh, LPT

Wellness Coordinator

Danielle Graniello, LVN

Wellness Coordinator

Michelle Cole, LVN

Wellness Coordinator

Maritza Nogueda, LVN

Wellness Coordinator

Madeline Clark, LVN

Wellness Coordinator

Michael Wahl

Environment of Care

Scott Ballard

Environment of Care

Anthony Portillo

Client Care Advocate

Abe Benavidas

Client Care Advocate

Rachel Corcoran

Client Care Advocate

Samantha Thien

Client Care Advocate

Stacy Elliot Johnson

Client Care Advocate

Robert Harrison

Client Care Advocate
Yanira Chavez

Yanira Chavez

Client Care Advocate

Lucas Barnett


Al Eiland


Paul Baumann


Dominique Gabriel



Our former clients say it best...

Dr. Stone, I am so grateful to your program and also your generosity. I was a hopeless addictwho believed there was no way of getting clean. Thanks to my sister and Cornerstone staff, I recently took my 90 day chip in N.A. Thanks, my life has been changed.
~ Isaac C.

“This was the best foundation I could have asked for to be sober. My case manager was the Best!! She showed me your life can be exciting and sober.”
~ Tina H.

It is the truly caring staff that makes Cornerstone the best rehab I have been to. The best part was finally getting my depression medications right, after many others tried for 2 years.
~ Jim V.

Licensed and Certified by the State of California Department of Healthcare Services.

We're here any time of the day to talk

Call us and speak to one of our caring addiction counsellors.

24 Hour Help (714) 547-5375

Scroll to Top