Registry data as of Aug 27, 2026

Mark Shiu, DO

Family Medicine Physician · Rancho Cucamonga, CA

Mark Shiu, DO is a family medicine physician with a practice address in Rancho Cucamonga, California, and NPI 1629004478, issued on Jun 23, 2006. Check the license (California 20A9372, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, loaded Aug 27, 2026 · Medicare files 2023 and 2024 · method · Verify with CMS →

NPPES recordas of Aug 27, 2026
1629004478
Name
Mark Shiu
Credential
DO
Primary taxonomy
Family Medicine Physician 207Q00000X
License number
20A9372 CA
Self-reported in NPPES; status is on the state search
Practice location
7974 Haven Ave, Rancho Cucamonga, CA 91730
Phone
(800) 734-1733
Enumerated
Jun 23, 2006
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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Also registered at 7974 Haven Ave

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

  1. Steven Barag, D.O.Family Medicine Physician1366444838
  2. Teresa Chang, L.AC.Acupuncturist1912212002
  3. Satish Choudhary, MDInterventional Cardiology Physician1669429841
  4. Christopher Ferraro, DCChiropractor1477656346
  5. Robert Gonzalez, DCChiropractor1891874822
  6. Mahmoud Ibrahim, MDPediatrics Physician1063451771

Verify Mark Shiu in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license 20A9372
    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.

Statewide context: the Medical Board of California reported 374 disciplinary actions in FY 2022-23. California discipline data →

33% more Medicare Part D claims than the average family medicine physician in 2024

4,697 Medicare Part D claims for 582 beneficiaries, against an average of 3,519 among the 111,126 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 61 claims were for opioids.

  1. Mark Shiu4,697
  2. Specialty average3,519

Most prescribed

  1. Atorvastatin Calcium483 claims
  2. Amlodipine Besylate192 claims
  3. Losartan Potassium175 claims
  4. Levothyroxine Sodium166 claims
  5. Metformin Hcl141 claims
  6. Rosuvastatin Calcium131 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.

Industry payments in 2024: $1,591.64

78 payments, mostly food and beverage; the largest payer was Abbvie Inc.. The 53,013 providers of this specialty with any payment received $861.30 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Mark Shiu$1,591.64
  2. Specialty average$861.30

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

One hospital or facility affiliation

  1. Gateway Medicor - Rancho Cucamonga IncRancho Cucamonga, CA

Source: CMS Doctors and Clinicians affiliations; Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.

58 family medicine physician records list a Rancho Cucamonga practice address

They are 58 of the 4,579 NPPES records with a Rancho Cucamonga practice address, and 16,272 family medicine physician records in California.

Other family medicine physician records in California

  1. Omer Aba-Omer, MDSanta Monica, CA1649702093
  2. Michelle Ababa, MDWilmington, CA1710922513
  3. Anna Tzeitel Abalos, MDRoseville, CA1720200017
  4. Adan Abarca, MDAnaheim, CA1760553689
  5. Vanessa Abarca, DOVentura, CA1952040859
  6. Lorraine Abate, M.D.Sacramento, CA1104840008
  7. Robert Abatecola, MDCastro Valley, CA1669551719
  8. Romeo Abaya, M.D.Cottonwood, CA1598053506
  9. Effiem Abbah, MD, MPHSan Francisco, CA1821185133
  10. Khuzeman Abbasi, MDSanta Rosa, CA1841979952

Common questions

What is Mark Shiu, DO's NPI number?

Mark Shiu, DO's National Provider Identifier (NPI) is 1629004478, issued on Jun 23, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Mark Shiu, DO located?

The NPPES record lists a practice address at 7974 Haven Ave, Rancho Cucamonga, CA, 91730. Phone: (800) 734-1733. Providers update this record themselves, so call before visiting.

How can I verify Mark Shiu, DO's license?

NPPES lists California license number 20A9372, 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 Mark Shiu, DO prescribe under Medicare Part D?

In 2024, Mark Shiu, DO had 4,697 Medicare Part D claims for 582 beneficiaries; the average among family medicine physician prescribers was 3,519. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 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.

Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 27, 2026.