NPPES file of Aug 9, 2026

Holly Hammack, LCSW

Clinical Social Worker · Fontana, CA

Holly Hammack, LCSW is a clinical social worker with a practice address in Fontana, California, and NPI 1295939338, issued on Jun 13, 2007. Check the license (California LCS10042, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.

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

NPPES recordNPPES file of Aug 9, 2026
1295939338
Name
Holly Hammack
Credential
LCSW
Primary taxonomy
Clinical Social Worker 1041C0700X
License number
LCS10042 CA
Self-reported in NPPES; status is on the state search
Practice location
9961 Sierra Ave, Fontana, CA 92335
Phone
(909) 427-3910
Enumerated
Jun 13, 2007
Record last updated
Sep 15, 2008 (not updated in 18 years: call before relying on the address or phone)
Medicare enrollment
Enrolled (PECOS I20110221000707); may accept Medicare assignment
Telehealth
Offers telehealth (CMS)
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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8 nearest clinical social worker records → All 36,261 in California → Look up another NPI →

Also registered at 9961 Sierra Ave

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

  1. Solomon Abila, MDFamily Medicine Physician1871652479
  2. Jenny Abouelsood, M.D.Family Medicine Physician1457638512
  3. Marla Abrolat, MDPediatrics Physician1164593133
  4. Eduardo Acosta, MDPediatrics Physician1497803324
  5. Michael Adair, MDFamily Medicine Physician1780732651
  6. Berneva Adams, MDObstetrics & Gynecology Physician1376602987

Verify Holly Hammack 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 LCS10042    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

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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Bills Medicare through one group practice

  1. Mountain View Behavioral Health IncUpland, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Holly Hammack among 36,261 clinical social worker records in California

Holly Hammack, LCSW is one of 36,261 clinical social worker records with a practice address in California. 6% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 9% of them.

  • NPI issued2007 · 9% of these records are older, 76% newer
  • In a Medicare fileYes · 6% of these records are
  • In the CMS Doctors and Clinicians fileYes · 11% of these records are
  • Graduated1980 · median 2012 among the 4,008 with a school on file
  • Record last updated2008 · 45% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 1041C0700X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

80 clinical social worker records list a practice address in Fontana

They are 80 of the 3,012 NPPES records with a practice address in Fontana, and 36,261 clinical social worker records in California.

All 36,261 in California → Every provider in Fontana → Clinical Social Worker nationwide →

The 8 clinical social worker records with the nearest ZIP codes

  1. Randall Alle-Corliss, LCSWFontana, CA 923351457404188
  2. Lupe Alle-Corliss, LCSWFontana, CA 923351558565697
  3. Cynthia Bousquet Harris, LCSWFontana, CA 923351710181862
  4. Rosemary Callopy, MFTFontana, CA 923351194929232
  5. Lisa Delgadillo, LCSWFontana, CA 923351891999033
  6. Victoria Delgadillo, LCSWFontana, CA 923351538363676
  7. Lois Heeren, L.C.S.W.Fontana, CA 923351942404389
  8. Joel Latimer, MFTFontana, CA 923351063616118

Common questions

What is Holly Hammack, LCSW's NPI number?

Holly Hammack, LCSW's National Provider Identifier (NPI) is 1295939338, issued on Jun 13, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Holly Hammack, LCSW located?

The NPPES record lists a practice address at 9961 Sierra Ave, Fontana, CA, 92335. Phone: (909) 427-3910. Providers update this record themselves, so call before visiting.

How can I verify Holly Hammack, LCSW's license?

NPPES lists California license number LCS10042, 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. 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.