Mental Health Therapist

Diana Seif

1556 S Sultana Ave, Ontario, California, 91761-4238

About Diana Seif

Diana Seif is a therapist based in Ontario, California who is specialized in Mental Health Counselor. Her current practice location is 1556 S Sultana Ave, Ontario. Patients can reach her at 909-418-6923. Diana Seif NPI number (Unique professional ID assigned by NPPES) is 1942571344.

Diana Seif is a licensed professional who helps individuals, couples, and families manage and overcome emotional, psychological, and behavioral challenges. She assess clients’ mental health conditions and develop personalized treatment plans to provide therapy for a range of mental health issues, including anxiety, depression, trauma, relationship issues, stress, grief, and life transitions.

Practice Information

Diana Seif speciality, credentials, practice address, contact phone number and fax are as below. Patients can call on the below given phone number for appointment.

Provider Name Diana Seif
Specialization Mental Health Counselor
Gender Female
Practice Address: 1556 S Sultana Ave,
Ontario, CA - 91761-4238

Professional Identification Codes

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

NPI Number1942571344
NPI Enumeration Date: 18 Jan, 2012
NPI Last Update On: 18 Jan, 2012

Medical Licenses:

Healthcare professionals can hold one or more medical licenses for different specialities in the same state or different states. Related medical licenses for Diana Seif are as mentioned below.

License NumberSpecializationStateStatus
Mental Health Counselor Primary

Mailing Address

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

Diana Seif
1556 S Sultana Ave,
Ontario, CA - 91761-4238
Phone: 909-418-6923

Book an Appointment with Diana Seif

To schedule an appointment, contact Diana Seif at 1556 S Sultana Ave, Ontario, California or call on below stated phone number.

Call to Book an Appointment

Frequently Asked Questions

Below are some commonly asked questions about Diana Seif:

Diana Seif is a therapist specializing in Mental Health Counselor. She is a licensed professional who helps individuals, couples, and families manage and overcome emotional, psychological, and behavioral challenges. She assess clients’ mental health conditions and develop personalized treatment plans to provide therapy for a range of mental health issues, including anxiety, depression, trauma, relationship issues, stress, grief, and life transitions.

Yes, Diana Seif is currently accepting new patients. To schedule an appointment, contact the office directly and schedule an appointment.

Diana Seif practices at 1556 S Sultana Ave, Ontario, California, 91761-4238.

To schedule an appointment with Diana Seif, please contact the office at 909-418-6923.

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