Tammy Eileen Lo, MMS, PA-C
Physician Assistant · Fullerton, CA
Tammy Eileen Lo, MMS, PA-C is a physician assistant with a practice address in Fullerton, California, and NPI 1891269502, issued on Jan 15, 2019. Check the license (California 56421, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Tammy Eileen Lo
- Credential
- MMS, PA-C
- Primary taxonomy
- Physician Assistant 363A00000X
- License number
- 56421 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2141 N Harbor Blvd Ste 25000, Fullerton, CA 92835
- Phone
- (714) 626-8650
- Enumerated
- Jan 15, 2019
- Record last updated
- Nov 5, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (714) 626-8654
- Medicare enrollment
- Enrolled (PECOS I20190508003373); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest physician assistant records → All 14,451 in California → Look up another NPI →
Also registered at 2141 N Harbor Blvd Ste 25000
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Hyacinth Lyre CabreraAmbulatory Care Registered Nurse1427949437
- Vanessa Franco, PA-CPhysician Assistant1609402114
- Jay Kim, M.D.Rheumatology Physician1811984123
Verify Tammy Eileen Lo in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 56421Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.8 times the Medicare Part D claims of the average physician assistant in 2024
2,352 Medicare Part D claims for 578 beneficiaries, against an average of 830 among the 101,058 providers of this specialty who prescribed in Part D. 13 claims were for opioids.
Most prescribed
- Amlodipine Besylate120 claims
- Gabapentin111 claims
- Atorvastatin Calcium103 claims
- Losartan Potassium102 claims
- Metoprolol Succinate95 claims
- Levothyroxine Sodium68 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: $45.09
2 payments; by number, the most common kind was food and beverage; the largest payer was GlaxoSmithKline, LLC. The 64,719 providers of this specialty with any payment received $841.65 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
- Providence Medical FoundationFullerton, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Tammy Eileen Lo among 14,451 physician assistant records in California
Tammy Eileen Lo, MMS, PA-C is one of 14,451 physician assistant records with a practice address in California. 75% 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 56% of them.
- NPI issued2019 · 56% of these records are older, 38% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 50% of these records are
- Graduated2018 · median 2018 among the 7,214 with a school on file
- Record last updated2021 · 40% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363A00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
138 physician assistant records list a practice address in Fullerton
They are 138 of the 5,437 NPPES records with a practice address in Fullerton, and 14,451 physician assistant records in California.
All 14,451 in California → Every provider in Fullerton → Physician Assistant nationwide →
The 8 physician assistant records with the nearest ZIP codes
- Shannon Cornwell, PAFullerton, CA 928351902961626
- Negeen Farmand, PAFullerton, CA 928351255530168
- Suzanne Freesemann, P.A.Fullerton, CA 928351285750430
- Melinda Garcia, PAFullerton, CA 928351437226263
- Erica Gomez, DMSC, MPAP, PA-CFullerton, CA 928351316044282
- Andrea Inskeep, PA-CFullerton, CA 928351578752424
- Elethea Locke-Harris, PA-CFullerton, CA 928351528196169
- Laura Lowry, PAFullerton, CA 928351841408390
Common questions
What is Tammy Eileen Lo, MMS, PA-C's NPI number?
Tammy Eileen Lo, MMS, PA-C's National Provider Identifier (NPI) is 1891269502, issued on Jan 15, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Tammy Eileen Lo, MMS, PA-C located?
The NPPES record lists a practice address at 2141 N Harbor Blvd Ste 25000, Fullerton, CA, 92835. Phone: (714) 626-8650. Providers update this record themselves, so call before visiting.
How can I verify Tammy Eileen Lo, MMS, PA-C's license?
NPPES lists California license number 56421, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Tammy Eileen Lo, MMS, PA-C prescribe under Medicare Part D?
In 2024, Tammy Eileen Lo, MMS, PA-C had 2,352 Medicare Part D claims for 578 beneficiaries; the average among physician assistant prescribers was 830. 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.