Ai (theresa) Diem Nguyen, O.D.
Optometrist · San Diego, CA
Ai (theresa) Diem Nguyen, O.D. is an optometrist with a practice address in San Diego, California, and NPI 1508857533, issued on Oct 31, 2005. Check the license (California OPT11481, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Ai (theresa) Diem Nguyen
- Credential
- O.D.
- Primary taxonomy
- Optometrist 152W00000X
- License number
- OPT11481 CA
Self-reported in NPPES; status is on the state search - Practice location
- 6945 EL Cajon Blvd, San Diego, CA 92115
- Phone
- (619) 697-4600
- Enumerated
- Oct 31, 2005
- Record last updated
- Feb 28, 2013 (not updated in 13 years: call before relying on the address or phone)
- Fax
- (619) 464-5526
- Medicaid ID
- GR0052930 CA
- Medicare enrollment
- Enrolled (PECOS I20050817000646); accepts Medicare assignment
- Medical or professional school
- Pennsylvania College Of Optometry, 2000
- Entity
- Type 1 · individual
8 nearest optometrist records → All 8,308 in California → Look up another NPI →
Also registered at 6945 EL Cajon Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Lauren Abo, O.D.Optometrist1588654719
- Sharon DyerOptometrist1063866887
- Barry Katzman, M.D.Ophthalmology Physician1760473797
- Yasmin Kouchak, O.DOptometrist1225316821
- Debra McIntyre, O.D.Optometrist1295810349
- Quang Nguyen, O.D.Optometrist1417948449
Verify Ai (theresa) Diem Nguyen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license OPT11481Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
68% fewer Medicare Part D claims than the average optometrist in 2024
90 Medicare Part D claims for 45 beneficiaries, against an average of 277 among the 33,128 providers of this specialty who prescribed in Part D. Brand-name drugs were 50% of claims.
Most prescribed
- Latanoprost43 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 80.3 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- California Eye ClinicAntioch, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Ai (theresa) Diem Nguyen among 8,308 optometrist records in California
Ai (theresa) Diem Nguyen, O.D. is one of 8,308 optometrist records with a practice address in California. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 94% newer
- In a Medicare fileYes · 67% of these records are
- In the CMS Doctors and Clinicians fileYes · 43% of these records are
- Graduated2000 · median 2008 among the 3,573 with a school on file
- Record last updated2013 · 67% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 152W00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Optometrist providers in California
There are 8,308 optometrist records in California.
All 8,308 in California → Every provider in San Diego → Optometrist nationwide →
The 8 optometrist records with the nearest ZIP codes
- Lauren Abo, O.D.San Diego, CA 921151588654719
- Usha Hari, O.D.San Diego, CA 921151891842399
- Yasmin Kouchak, O.DSan Diego, CA 921151225316821
- Debra McIntyre, O.D.San Diego, CA 921151295810349
- Quang Nguyen, O.D.San Diego, CA 921151417948449
- Norman Ratner, O.D.San Diego, CA 921151811094709
- Jennifer Salvo, O.D.San Diego, CA 921151336453729
- Videnne Sath, O.D.San Diego, CA 921151851604540
Common questions
What is Ai (theresa) Diem Nguyen, O.D.'s NPI number?
Ai (theresa) Diem Nguyen, O.D.'s National Provider Identifier (NPI) is 1508857533, issued on Oct 31, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Ai (theresa) Diem Nguyen, O.D. located?
The NPPES record lists a practice address at 6945 EL Cajon Blvd, San Diego, CA, 92115. Phone: (619) 697-4600. Providers update this record themselves, so call before visiting.
How can I verify Ai (theresa) Diem Nguyen, O.D.'s license?
NPPES lists California license number OPT11481, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Ai (theresa) Diem Nguyen, O.D. prescribe under Medicare Part D?
In 2024, Ai (theresa) Diem Nguyen, O.D. had 90 Medicare Part D claims for 45 beneficiaries; the average among optometrist prescribers was 277. Part D covers Medicare prescriptions only.
What is Ai (theresa) Diem Nguyen, O.D.'s MIPS final score?
The 2023 MIPS final score is 80.3 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.