Michael Tieu Loi, DO
Internal Medicine Physician · Irvine, CA
Michael Tieu Loi, DO is an internal medicine physician with a practice address in Irvine, California, and NPI 1861057556, issued on May 8, 2019. Check the license (California 20A22634, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Michael Tieu Loi
- Credential
- DO
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 20A22634 CA
Self-reported in NPPES; status is on the state search - Practice location
- 11 Technology Dr, Irvine, CA 92618
- Phone
- (949) 923-3200
- Enumerated
- May 8, 2019
- Record last updated
- Nov 23, 2025
- Medicare enrollment
- Enrolled (PECOS I20240515002227); accepts Medicare assignment
- Medical or professional school
- At Still Un Of Hlth Sciences, Col Of Osteo Med, Mesa, 2021
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 11 Technology Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Michael Tieu Loi in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license 20A22634Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
95% fewer Medicare Part D claims than the average internal medicine physician in 2024
166 Medicare Part D claims for 52 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 13% of 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: $680.71
9 payments; by number, the most common kind was food and beverage; the largest payer was Janssen Pharmaceuticals, Inc. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Centers For Family Medicine GPLaguna Hills, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Michael Tieu Loi among 17,696 internal medicine physician records in California
Michael Tieu Loi, DO 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 2019, is newer than 86% of them.
- NPI issued2019 · 86% of these records are older, 11% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2021 · median 2004 among the 11,065 with a school on file
- Record last updated2025 · 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).
155 internal medicine physician records list a practice address in Irvine
They are 155 of the 7,778 NPPES records with a practice address in Irvine, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Irvine → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Savitha Bharadwaj, M.D.Irvine, CA 926181760470926
- Juan Cabrera, M.D.Irvine, CA 926181447254792
- William Chen, M.D.Irvine, CA 926181881659142
- Subrato Ghosh, MDIrvine, CA 926181083607055
- Kambiz Karimi, M.D.Irvine, CA 926181184688475
- Sara Kim, M.D.Irvine, CA 926181912944166
- Brian Lo, MDIrvine, CA 926181073501565
- Emad Mikhail, MDIrvine, CA 926181376582957
Common questions
What is Michael Tieu Loi, DO's NPI number?
Michael Tieu Loi, DO's National Provider Identifier (NPI) is 1861057556, issued on May 8, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Michael Tieu Loi, DO located?
The NPPES record lists a practice address at 11 Technology Dr, Irvine, CA, 92618. Phone: (949) 923-3200. Providers update this record themselves, so call before visiting.
How can I verify Michael Tieu Loi, DO's license?
NPPES lists California license number 20A22634, 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 Michael Tieu Loi, DO prescribe under Medicare Part D?
In 2024, Michael Tieu Loi, DO had 166 Medicare Part D claims for 52 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.