NPPES file of Aug 9, 2026

William Mack Erwin, PH.D.

Clinical Psychologist · San Antonio, TX

William Mack Erwin, PH.D. is a clinical psychologist with a practice address in San Antonio, Texas, and NPI 1063562684, issued on Jan 12, 2007. Check the license (Texas 20855, as entered in NPPES) with the Texas 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
1063562684
Name
William Mack Erwin
Credential
PH.D.
Primary taxonomy
Clinical Psychologist 103TC0700X
License number
20855 TX
Self-reported in NPPES; status is on the state search
Practice location
14815 San Pedro Ave, San Antonio, TX 78232
Phone
(210) 494-1991
Enumerated
Jan 12, 2007
Record last updated
Jan 5, 2011 (not updated in 15 years: call before relying on the address or phone)
Fax
(210) 494-7575
Medicare enrollment
Enrolled (PECOS I20100303000190); accepts Medicare assignment
Medical or professional school
Texas Tech University Health Science Center School Of Medicine, 1971
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.
Download card Updates feed

8 nearest clinical psychologist records → All 2,732 in Texas → Look up another NPI →

Also registered at 14815 San Pedro Ave

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

  1. Evelyn McNeel, LPC, LCDC, AACAddiction (Substance Use Disorder) Counselor1841345048
  2. Austin McNeel Siegel, LPCMental Health Counselor1669481347
  3. Nancy Ratliff, PH.D.Health Service Psychologist1437296753
  4. Brian Skop, MDPsychiatry Physician1134220676
  5. Eva Lynn Walthall, LCSWClinical Social Worker1548332778
  6. William Yates, PH.D.Clinical Child & Adolescent Psychologist1629086301

Verify William Mack Erwin in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich Texas board licenses this profession
    Search for license 20855    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 Texas 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.

Is this page about you? You can ask us to correct, restrict or remove it: how.

William Mack Erwin among 2,732 clinical psychologist records in Texas

William Mack Erwin, PH.D. is one of 2,732 clinical psychologist records with a practice address in Texas. 14% 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 2007, is newer than 28% of them.

  • NPI issued2007 · 28% of these records are older, 58% newer
  • In a Medicare fileNo · 14% of these records are
  • In the CMS Doctors and Clinicians fileYes · 22% of these records are
  • Graduated1971 · median 2006 among the 598 with a school on file
  • Record last updated2011 · 62% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 103TC0700X and a Texas practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Clinical Psychologist providers in Texas

There are 2,732 clinical psychologist records in Texas. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

All 2,732 in Texas → Every provider in San Antonio → Clinical Psychologist nationwide →

The 8 clinical psychologist records with the nearest ZIP codes

  1. Franklin Brooks, PH.D.San Antonio, TX 782321588690317
  2. Ruth Bujanda-Moore, PSY.D.San Antonio, TX 782321316199045
  3. Diane Coalson, PHD, LPSan Antonio, TX 782321063990976
  4. Fernando Esparza, PSY D.San Antonio, TX 782321992753701
  5. Katrina Hallmark, PSYDSan Antonio, TX 782321285708420
  6. Gabriel Holguin, PH.D.San Antonio, TX 782321952319998
  7. Claire Jacobs, PH.D.San Antonio, TX 782321043200496
  8. Christina Lion, PHD., M.P.T.San Antonio, TX 782321841516572

Common questions

What is William Mack Erwin, PH.D.'s NPI number?

William Mack Erwin, PH.D.'s National Provider Identifier (NPI) is 1063562684, issued on Jan 12, 2007. An NPI identifies a provider in billing; it is not a license.

Where is William Mack Erwin, PH.D. located?

The NPPES record lists a practice address at 14815 San Pedro Ave, San Antonio, TX, 78232. Phone: (210) 494-1991. Providers update this record themselves, so call before visiting.

How can I verify William Mack Erwin, PH.D.'s license?

NPPES lists Texas license number 20855, as entered by the provider. Search the Texas 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.