NPPES file of Aug 9, 2026

Matthew Clark

Addiction (Substance Use Disorder) Counselor · Upland, CA

Matthew Clark is an addiction (substance use disorder) counselor with a practice address in Upland, California, and NPI 1538930045, issued on Jan 12, 2024. Check the license (California R1503700423, as entered in NPPES) with the California board that licenses this profession; the federal record below is the public data PlainDoctor holds for this provider.

Record from CMS NPPES, file of Aug 9, 2026 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1538930045
Name
Matthew Clark
Primary taxonomy
Addiction (Substance Use Disorder) Counselor 101YA0400X
License number
R1503700423 CA
Self-reported in NPPES; status is on the state search
Practice location
239 W 9TH St, Upland, CA 91786
Phone
(909) 340-4276
Enumerated
Jan 12, 2024
Record last updated
May 30, 2024
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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8 nearest addiction (substance use disorder) counselor records → All 27,741 in California → Look up another NPI →

Also registered at 239 W 9TH St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Carol AlvarezAddiction (Substance Use Disorder) Counselor1386103497
  2. Zachary BarriaultAddiction (Substance Use Disorder) Counselor1750007449
  3. Mahmoud BensufiaPeer Specialist1205783230
  4. Chris CarrilloAddiction (Substance Use Disorder) Counselor1578196671
  5. Melissa CervantesAddiction (Substance Use Disorder) Counselor1306502869
  6. Justin CiasulloAddiction (Substance Use Disorder) Counselor1346068624

Verify Matthew Clark in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich California board licenses this profession
    Search for license R1503700423    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Find the California license search

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Matthew Clark among 27,741 addiction (substance use disorder) counselor records in California

Matthew Clark is one of 27,741 addiction (substance use disorder) counselor records with a practice address in California. under 1% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2024, is newer than 82% of them.

  • NPI issued2024 · 82% of these records are older, 10% newer
  • In a Medicare fileNo · under 1% of these records are
  • In the CMS Doctors and Clinicians fileNo · under 1% of these records are
  • Record last updated2024 · 59% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 101YA0400X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

170 addiction (substance use disorder) counselor records list a practice address in Upland

They are 170 of the 1,846 NPPES records with a practice address in Upland, and 27,741 addiction (substance use disorder) counselor records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

All 27,741 in California → Every provider in Upland → Addiction (Substance Use Disorder) Counselor nationwide →

The 8 addiction (substance use disorder) counselor records with the nearest ZIP codes

  1. Cynthia AbeytaUpland, CA 917861154516250
  2. Becky Baker, CADDTPUpland, CA 917861467788315
  3. Yvonne Barron, CADC-IIUpland, CA 917861154551687
  4. Tyler CarrollUpland, CA 917861700021433
  5. Janice Degrande, CASUpland, CA 917861245387687
  6. Robert FullerUpland, CA 917861609998459
  7. Robert Gallegos, CADC IIUpland, CA 917861669697322
  8. Angel GuillenUpland, CA 917861316250541

Common questions

What is Matthew Clark's NPI number?

Matthew Clark's National Provider Identifier (NPI) is 1538930045, issued on Jan 12, 2024. An NPI identifies a provider in billing; it is not a license.

Where is Matthew Clark located?

The NPPES record lists a practice address at 239 W 9TH St, Upland, CA, 91786. Phone: (909) 340-4276. Providers update this record themselves, so call before visiting.

How can I verify Matthew Clark's license?

NPPES lists California license number R1503700423, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.