NPPES file of Aug 9, 2026

Mark Leonard Katz, M.D.

Addiction Psychiatry Physician · Long Beach, CA

Mark Leonard Katz, M.D. is an addiction psychiatry physician with a practice address in Long Beach, California, and NPI 1558478941, issued on Aug 23, 2006. Check the license (California G 62277, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1558478941
Name
Mark Leonard Katz
Credential
M.D.
Primary taxonomy
Addiction Psychiatry Physician 2084P0802X
License number
G 62277 CA
Self-reported in NPPES; status is on the state search
Practice location
5901 E 7TH St, Long Beach, CA 90822
Phone
(562) 826-8000
Enumerated
Aug 23, 2006
Record last updated
Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
Fax
(562) 826-5431
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 psychiatry physician records → All 73 in California → Look up another NPI →

Also registered at 5901 E 7TH St

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

  1. Nneoma Achikam, LCSW, BCDClinical Social Worker1114182953
  2. Sameera Ahmad, ODOptometrist1164117891
  3. Sama Alabbas, PHARMDPharmacist1366165193
  4. Lawrence Albers, MDPsychiatry Physician1871697300
  5. Abby AlexanderOptometrist1871113068
  6. Tamara Alexander, PT, DPTPhysical Therapist1922116714

Verify Mark Leonard Katz in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G 62277    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
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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Industry payments in 2024: $62.15

1 payment: food and beverage; the largest payer was Ambu Inc. The 170 providers of this specialty with any payment received $1,785.85 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Mark Katz$62.15
  2. Specialty average$1,785.85

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Mark Leonard Katz among 73 addiction psychiatry physician records in California

Mark Leonard Katz, M.D. is one of 73 addiction psychiatry physician records with a practice address in California. 73% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 4% of them.

  • NPI issued2006 · 4% of these records are older, 58% newer
  • In a Medicare fileYes · 73% of these records are
  • In the CMS Doctors and Clinicians fileNo · 34% of these records are
  • Record last updated2007 · 56% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2084P0802X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Addiction Psychiatry Physician providers in California

There are 73 addiction psychiatry physician records in California.

All 73 in California → Every provider in Long Beach → Addiction Psychiatry Physician nationwide →

The 8 addiction psychiatry physician records with the nearest ZIP codes

  1. Ricardo Restrepo-Guzman, M.DLong Beach, CA 908221891720512
  2. Milagros Demandante, MDLong Beach, CA 908041134342041
  3. Stephen Mohaupt, M.D.Norwalk, CA 906501982792990
  4. Eva Altobelli, MDSanta Monica, CA 904041790990620
  5. Timothy Hayes, M.D., M.P.H.Santa Monica, CA 904041194722264
  6. William Huang, M.D.Santa Monica, CA 904031295787166
  7. Evelina WeinsteinSanta Monica, CA 904011891023842
  8. Steven Allen, M.D.Sylmar, CA 913421700144557

Common questions

What is Mark Leonard Katz, M.D.'s NPI number?

Mark Leonard Katz, M.D.'s National Provider Identifier (NPI) is 1558478941, issued on Aug 23, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Mark Leonard Katz, M.D. located?

The NPPES record lists a practice address at 5901 E 7TH St, Long Beach, CA, 90822. Phone: (562) 826-8000. Providers update this record themselves, so call before visiting.

How can I verify Mark Leonard Katz, M.D.'s license?

NPPES lists California license number G 62277, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. 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.