NPPES file of Aug 9, 2026

Barry Steven Allswang, MD

Internal Medicine Physician · Los Alamitos, CA

Barry Steven Allswang, MD is an internal medicine physician with a practice address in Los Alamitos, California, and NPI 1720016397, issued on Jun 30, 2006. Check the license (California G34791, 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
1720016397
Name
Barry Steven Allswang
Credential
MD
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
G34791 CA
Self-reported in NPPES; status is on the state search
Practice location
3801 Katella Ave, Los Alamitos, CA 90720
Phone
(562) 594-9546
Enumerated
Jun 30, 2006
Record last updated
Sep 7, 2007 (not updated in 19 years: call before relying on the address or phone)
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.
Download card Updates feed

Also registered at 3801 Katella Ave

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

  1. Abes Bagheri, M.D.Geriatric Psychiatry Physician1073619789
  2. Myron Bloom, MDPlastic and Reconstructive Surgery Physician1881608370
  3. Mitch Bovy, O.D.Optometrist1215331269
  4. Georganne Cashdollar, N.P.Primary Care Nurse Practitioner1578860086
  5. Mark Castellanet, M.D.Cardiovascular Disease Physician1538165782
  6. Winston Chung, MDInternal Medicine Physician1851322085

Verify Barry Steven Allswang in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G34791
    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.

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

96% fewer Medicare Part D claims than the average internal medicine physician in 2024

129 Medicare Part D claims for 60 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.

  1. Barry Allswang129
  2. Specialty average3,176

Most prescribed

  1. Amlodipine Besylate15 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

Barry Steven Allswang among 17,696 internal medicine physician records in California

Barry Steven Allswang, MD is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 5% of them.

  • NPI issued2006 · 5% of these records are older, 56% newer
  • In a Medicare fileYes · 79% of these records are
  • In the CMS Doctors and Clinicians fileNo · 63% of these records are
  • Record last updated2007 · 61% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

40 internal medicine physician records list a practice address in Los Alamitos

They are 40 of the 1,035 NPPES records with a practice address in Los Alamitos, and 17,696 internal medicine physician records in California.

The 8 internal medicine physician records with the nearest ZIP codes

  1. Carlos ArguedasLos Alamitos, CA 907201023075579
  2. Vichai Bhoopat, M.D.Los Alamitos, CA 907201841211497
  3. Winston Chung, MDLos Alamitos, CA 907201851322085
  4. Gerald Cohen, MDLos Alamitos, CA 907201306877253
  5. Heena Contractor, M.D.Los Alamitos, CA 907201518954973
  6. William Harrell, MDLos Alamitos, CA 907201083673685
  7. Taolin Jen, M.D.Rossmoor, CA 907201457384828
  8. Harold Lin, M.D.Los Alamitos, CA 907201467472472

Common questions

What is Barry Steven Allswang, MD's NPI number?

Barry Steven Allswang, MD's National Provider Identifier (NPI) is 1720016397, issued on Jun 30, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Barry Steven Allswang, MD located?

The NPPES record lists a practice address at 3801 Katella Ave, Los Alamitos, CA, 90720. Phone: (562) 594-9546. Providers update this record themselves, so call before visiting.

How can I verify Barry Steven Allswang, MD's license?

NPPES lists California license number G34791, 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.

How much does Barry Steven Allswang, MD prescribe under Medicare Part D?

In 2024, Barry Steven Allswang, MD had 129 Medicare Part D claims for 60 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions 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.

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.