MR. MATTHEW GRELLING M.A. M.F.T.
NPI 1831239037
Counselor - Mental Health in Diamond Bar, CA

Q: What is Matthew Grelling's NPI number?

The NPI number for Matthew Grelling is 1831239037. It was assigned to this individual provider in the NPPES registry on February 7, 2007.

Q: What is Matthew Grelling's specialty?

The primary specialty registered for this NPI is Counselor, specializing in Mental Health, with taxonomy code 101YM0800X.

Q: When was this NPI record last updated?

The NPPES record for Matthew Grelling was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since February 07, 2007

1111 GRAND AVE STE J, DIAMOND BAR, CA 91765(951) 505-0019 Get Directions Write a Review

NPPES record last updated: July 8, 2007. Verified against the NPPES registry weekly; last sync: August 02, 2026.

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About Mr. Matthew Grelling M.a. M.f.t. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

MR. MATTHEW GRELLING M.A. M.F.T. (NPI 1831239037) is an individual mental health provider in Diamond Bar, California, licensed in California (MFT 35675) and active in the NPI registry since February 2007.

NPPES Registry Identity

NPI1831239037

Entity TypeIndividualMale

Primary Taxonomy101YM0800X

Provider Legal NameMR. MATTHEW GRELLINGCredential: M.A. M.F.T.

Location Address1111 GRAND AVE STE JDiamond Bar, CA 91765-4172

Mailing Address732 Occidental DrClaremont, CA 91711-2632 · (951) 505-0019

Phone(951) 505-0019

Sole ProprietorYes

Enumeration DateFebruary 7, 2007

Last NPPES UpdateJuly 8, 2007

✔ NPI 1831239037 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyCounselor · Mental HealthBehavioral Health & Social Service Providers

Taxonomy Code101YM0800X

License✔ Licensed in CA · MFT 35675

1111 GRAND AVE STE J, Diamond Bar, CA 91765

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Other Providers at the Same Location NPPES

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

YEYONGSHIN DO INC

Family Medicine

1111 GRAND AVE STE J
DIAMOND BAR, CA 91765

Los Angeles County (909) 306-4102

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Matthew Grelling's NPI number?

The NPI number for Matthew Grelling is 1831239037. It was assigned to this individual provider in the NPPES registry on February 7, 2007.

Where is Matthew Grelling located?

Matthew Grelling practices at 1111 Grand Ave Ste J, Diamond Bar, CA 91765. The listed phone number is (951) 505-0019.

What is Matthew Grelling's specialty?

The primary specialty registered for this NPI is Counselor, specializing in Mental Health, with taxonomy code 101YM0800X.

When was this NPI record last updated?

The NPPES record for Matthew Grelling was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.