Melissa Siew, M.D.
Internal Medicine Physician · Westminster, CA
Melissa Siew, M.D. is an internal medicine physician with a practice address in Westminster, California, and NPI 1780096099, issued on May 21, 2014. Check the license (California A132081, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Melissa Siew
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A132081 CA
Self-reported in NPPES; status is on the state search - Practice location
- 7955 Westminster Blvd, Westminster, CA 92683
- Phone
- (714) 379-3221
- Enumerated
- May 21, 2014
- Record last updated
- Sep 18, 2015 (not updated in 11 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20151020002779); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 7955 Westminster Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Khaled Chan, MDInternal Medicine Physician1255376414
- Patricia Farnam, PA-CPhysician Assistant1982914792
- Erica Finley Hickey, PAPhysician Assistant1487699658
- Victoria Greblya, MDInternal Medicine Physician1790720969
- Allison Hallinan, P.A.-CPhysician Assistant1760521330
- Helen Khalafbeigi, M.D.Family Medicine Physician1386834091
Verify Melissa Siew in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A132081Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
9% more Medicare Part D claims than the average internal medicine physician in 2024
3,458 Medicare Part D claims for 291 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. 54 claims were for opioids.
Most prescribed
- Levothyroxine Sodium198 claims
- Atorvastatin Calcium126 claims
- Quetiapine Fumarate124 claims
- Furosemide103 claims
- Donepezil Hcl95 claims
- Famotidine93 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): 76.7 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).
Melissa Siew among 17,696 internal medicine physician records in California
Melissa Siew, M.D. 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 2014, is newer than 74% of them.
- NPI issued2014 · 74% of these records are older, 24% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2012 · median 2004 among the 11,065 with a school on file
- Record last updated2015 · 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).
43 internal medicine physician records list a practice address in Westminster
They are 43 of the 1,306 NPPES records with a practice address in Westminster, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Westminster → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Loc Bui, M.D.Westminster, CA 926831023081387
- Andy Ho, M.D.Westminster, CA 926831801850821
- Vu Le, M.D.Westminster, CA 926831013992791
- Dean Ngo, MDWestminster, CA 926831982690582
- Loan Ngo, M.D.Westminster, CA 926831386696144
- Phuc Nguyen, M.D.Westminster, CA 926831134123961
- Vuong Nguyen, M.D.Westminster, CA 926831093701690
- Hoa Nguyen, M.DWestminster, CA 926831619931763
Common questions
What is Melissa Siew, M.D.'s NPI number?
Melissa Siew, M.D.'s National Provider Identifier (NPI) is 1780096099, issued on May 21, 2014. An NPI identifies a provider in billing; it is not a license.
Where is Melissa Siew, M.D. located?
The NPPES record lists a practice address at 7955 Westminster Blvd, Westminster, CA, 92683. Phone: (714) 379-3221. Providers update this record themselves, so call before visiting.
How can I verify Melissa Siew, M.D.'s license?
NPPES lists California license number A132081, 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 Melissa Siew, M.D. prescribe under Medicare Part D?
In 2024, Melissa Siew, M.D. had 3,458 Medicare Part D claims for 291 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Melissa Siew, M.D.'s MIPS final score?
The 2023 MIPS final score is 76.7 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.