Charles Hsiao-Kung Feng, MD
Allergy & Immunology Physician · Mountain View, CA
Charles Hsiao-Kung Feng, MD is an allergy & immunology physician with a practice address in Mountain View, California, and NPI 1518260306, issued on Dec 16, 2010. Check the license (California A115080, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Charles Hsiao-Kung Feng
- Credential
- MD
- Primary taxonomy
- Allergy & Immunology Physician 207K00000X
- License number
- A115080 CA
Self-reported in NPPES; status is on the state search - Practice location
- 701 E EL Camino Real, Mountain View, CA 94040
- Phone
- (650) 934-7888
- Enumerated
- Dec 16, 2010
- Record last updated
- Sep 23, 2015 (not updated in 11 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20130619000536); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest allergy & immunology physician records → All 444 in California → Look up another NPI →
Also registered at 701 E EL Camino Real
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Olga Afanasiev, MD, PHDDermatology Physician1669869384
Verify Charles Hsiao-Kung Feng in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A115080Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
53% fewer Medicare Part D claims than the average allergy & immunology physician in 2024
345 Medicare Part D claims for 75 beneficiaries, against an average of 741 among the 2,899 providers of this specialty who prescribed in Part D. Brand-name drugs were 38% of claims.
Most prescribed
- Azelastine Hcl39 claims
- Ipratropium Bromide32 claims
- Dupixent Pen27 claims
- Fluticasone Propionate21 claims
- Azelastine-Fluticasone17 claims
- Flunisolide16 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.
Bills Medicare through one group practice
- Sutter Bay Medical FoundationLos Gatos, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Charles Hsiao-Kung Feng among 444 allergy & immunology physician records in California
Charles Hsiao-Kung Feng, MD is one of 444 allergy & immunology 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 2010, is newer than 71% of them.
- NPI issued2010 · 71% of these records are older, 26% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2009 · median 2004 among the 281 with a school on file
- Record last updated2015 · 62% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207K00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Allergy & Immunology Physician providers in California
There are 444 allergy & immunology physician records in California.
All 444 in California → Every provider in Mountain View → Allergy & Immunology Physician nationwide →
The 8 allergy & immunology physician records with the nearest ZIP codes
- Philippe Begin, M.D.Mountain View, CA 940401386065902
- Patty Chi, MDMountain View, CA 940401407898323
- Jamila Martin, M.D.Mountain View, CA 940401316164106
- Cindy Nguyen, D.O.Mountain View, CA 940401558893297
- Manjul Dixit, MDAtherton, CA 940271922064963
- Nancy Cummings, MDMenlo Park, CA 940251598728917
- Jenna Nguyen, MDMenlo Park, CA 940251437492147
- Anna Postolova, MDMenlo Park, CA 940251932475316
Common questions
What is Charles Hsiao-Kung Feng, MD's NPI number?
Charles Hsiao-Kung Feng, MD's National Provider Identifier (NPI) is 1518260306, issued on Dec 16, 2010. An NPI identifies a provider in billing; it is not a license.
Where is Charles Hsiao-Kung Feng, MD located?
The NPPES record lists a practice address at 701 E EL Camino Real, Mountain View, CA, 94040. Phone: (650) 934-7888. Providers update this record themselves, so call before visiting.
How can I verify Charles Hsiao-Kung Feng, MD's license?
NPPES lists California license number A115080, 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 Charles Hsiao-Kung Feng, MD prescribe under Medicare Part D?
In 2024, Charles Hsiao-Kung Feng, MD had 345 Medicare Part D claims for 75 beneficiaries; the average among allergy & immunology physician prescribers was 741. 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.