Psychologist | Clinical Psychology

Dr. Mark Stephen Lum, PSY.D.

1801 E Heim Ave, Suite 204, Orange, California, 92865-3020

About Dr. Mark Stephen Lum

Dr. Mark Stephen Lum is a psychologist based in Orange, California who is specialized in Clinical Psychology. Active license number of Dr. Mark Stephen Lum is PSY13344 for Clinical Psychology in California. His current practice location is 1801 E Heim Ave, Suite 204, Orange. Patients can contact him at 714-282-9713 or can fax him at 714-282-8016. Dr. Mark Stephen Lum, PSY.D., specializes in Clinical Psychology and his NPI number (Unique professional ID assigned by NPPES) is 1083648752.

Dr. Mark Stephen Lum is a mental health professional with highly specialized training in the diagnosis and psychological treatment of mental, behavioral and emotional illnesses, including obsessive-compulsive disorder (OCD). His main focus is on diagnosing and treating mental, emotional, and behavioral disorders. Some of the common disorders that he can treat are learning disabilities, substance abuse, depression, anxiety, and eating disorders.

Practice Information

Dr. Mark Stephen Lum's specialty, credentials, practice address, contact phone number and fax are as below. Patients can call on the below given phone number for appointment.

Provider Name Dr. Mark Stephen Lum
Specialization Clinical Psychology
Credentials PSY.D.
Gender Male
Practice Address: 1801 E Heim Ave, Suite 204
Orange, CA - 92865-3020
Fax 714-282-8016

Professional Identification Codes

NPI number stands for National Provider Identifier which is a unique 10-digit identification number issued to healthcare providers in the United States by the Centers for Medicare and Medicaid Services (CMS). NPI details are as mentioned below.

NPI Number1083648752
NPI Enumeration Date: 10 Jul, 2006
NPI Last Update On: 20 Sep, 2007

Medical Licenses:

Healthcare professionals can hold one or more medical licenses for different specialties in the same state or different states. Related medical licenses for Dr. Mark Stephen Lum are as mentioned below.

License NumberSpecializationStateStatus
PSY13344Clinical Psychology CaliforniaPrimary

Mailing Address

Business mailing address can be used for mailing purpose only, for visiting purpose patients need to refer above mentioned Practice address.

Dr. Mark Stephen Lum
Po Box 80736,
Rancho Santa Margarita, CA - 92688-0736
Phone: 949-713-9846
Fax: 949-713-9846

Book an Appointment with Dr. Mark Stephen Lum

To schedule an appointment, contact Dr. Mark Stephen Lum at 1801 E Heim Ave, Suite 204, Orange, California or call the phone number listed below.

Book an Appointment

Frequently Asked Questions

Below are some commonly asked questions about Dr. Mark Stephen Lum:

Dr. Mark Stephen Lum is a psychologist specializing in Clinical Psychology. He is a mental health professional with highly specialized training in the diagnosis and psychological treatment of mental, behavioral and emotional illnesses, including obsessive-compulsive disorder (OCD). His main focus is on diagnosing and treating mental, emotional, and behavioral disorders. Some of the common disorders that he can treat are learning disabilities, substance abuse, depression, anxiety, and eating disorders.

Yes, Dr. Mark Stephen Lum is currently accepting new patients. To schedule an appointment, contact the office directly and schedule an appointment.
*Availability may change. Please contact the office directly to ask about appointments.

Dr. Mark Stephen Lum practices at 1801 E Heim Ave, Suite 204, Orange, California, 92865-3020.

To schedule an appointment with Dr. Mark Stephen Lum, please contact the office at 714-282-9713.

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**Data of this site is collected from Medicare & Medicaid Services (CMS) and NPPES. Last updated on 14 September, 2026.