Dr. Irving Chen , PharmD
Pharmacist • Greenbrae, CA
330 Bon Air Ctr
Greenbrae, CA 949043017
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
-
NPI assigned on April 10, 2020; this date does not establish years in practice.
-
Published CMS data list 24 Medicare Part D prescriptions, including refills, in 2024.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024. Published rows only; this is not a quality measure.
-
Published Part D records, 2024:
- Shingrix (Varicella-Zoster Ge/As01b/Pf) — 24 prescription fills, including refills.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024. Drug names come from pharmacy claims. Listing a drug here is not an endorsement or a recommendation.
See the full table · Guide: How to read Medicare Part D prescriber data
-
Fewer Part D prescriptions than 80% of clinicians listed under Pharmacist in California (2024, 4,002 clinicians with data). Median for this group: 64. Middle half: 32 to 128.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024. Billing and prescribing volume is not a quality rating.
-
Medicare Part D prescriptions went from 12 in 2021 to 24 in 2024.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2021–2024.
Practice Location & Contact Primary Location
330 Bon Air Ctr
Greenbrae, CA 949043017
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Pharmacist: NPPES taxonomy is a reported classification, not proof of board certification.
30-day fills
24 standardized 30-day fills in 2024
CMS converts prescriptions to 30-day supplies so they can be compared. A 90-day prescription counts as about three 30-day fills.
What this does not show: 30-day fills
It is not a count of patients and not a measure of quality.
Part D drug cost
$4,803 in 2024
The total cost of these prescriptions in 2024, paid by Medicare drug plans, patients and other payers together.
It shows the total spending on drugs this clinician prescribed, not what any one patient paid.
What this does not show: Part D drug cost
A higher cost often reflects the type of medicines a specialty uses. It is not your out-of-pocket cost and not a measure of quality.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024.
NPI first issued
2020
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians; Medicare.gov, “Does your provider accept Medicare as full payment?”
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Compared with the same specialty in Greenbrae and California
Billing and prescribing volume is not a quality rating.
Medicare Part D prescriptions
Fewer Part D prescriptions than 80% of clinicians listed under Pharmacist in California (2024, 4,002 clinicians with data). Median for this group: 64. Middle half: 32 to 128.
Too few clinicians listed under Pharmacist in Greenbrae have Medicare Part D data for 2024 to compare.
Part D drug cost
A lower Part D drug cost than 75% of clinicians listed under Pharmacist in California (2024, 4,002 clinicians with data). Median for this group: $13,282. Middle half: $6,203 to $25,065.
Too few clinicians listed under Pharmacist in Greenbrae have Medicare Part D data for 2024 to compare.
24 active clinicians are listed under Pharmacist with a practice address in Greenbrae, CA (32,552 in California).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Greenbrae
0% of these 24 clinicians have the CMS telehealth indicator.
0% of these 24 clinicians are listed by CMS as accepting Medicare assignment.
CMS data by year
Changes may reflect reporting, coverage or privacy limits, not changes in care quality.
-
Medicare Part D prescriptions
Medicare Part D prescriptions went from 12 in 2021 to 24 in 2024.
- 2021: 12
- 2022: 11
- 2023: 54
- 2024: 24
-
30-day fills
30-day fills went from 12 in 2021 to 24 in 2024.
- 2021: 12
- 2022: 11
- 2023: 54
- 2024: 24
-
Part D drug cost
Part D drug cost increased 136% from $2,033 in 2021 to $4,803 in 2024.
- 2021: $2,033
- 2022: $2,016
- 2023: $13,597
- 2024: $4,803
Sources: CMS Medicare Part D Prescribers (2024), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo · Report an error.
Medicare Part D Prescribing Profile & Medications
Medicare Part D prescriptions filled, including refills, in 2024.
| Brand Name | Generic Name | Prescriptions | Day Supply | Total Cost | Patients |
|---|---|---|---|---|---|
| Shingrix | Varicella-Zoster Ge/As01b/Pf | 24 | 24 | $4,802.81 | 20 |
Source: CMS Part D by Provider and Drug, 2024; rows below 11 claims omitted by CMS; volume isn’t quality. Privacy limits
Specialties & License Numbers Reported to NPPES
Self-certified to NPPES: 2020-04-10NUCC Taxonomy Code: 183500000X
An individual licensed by the appropriate state regulatory agency to engage in the practice of pharmacy. The practice of pharmacy includes, but is not limited to, assessment, interpretation, evaluation, and implementation, initiation, monitoring or modification of medication and or medical orders; the compounding or dispensing of medication and or medical orders; participation in drug and device procurement, storage, and selection; drug administration; drug regimen reviews; drug or drug-related research; provision of patient education and the provision of those acts or services necessary to provide medication therapy management services in all areas of patient care.
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Pharmacist
Pharmacist
Doctor of Pharmacy (Pharm.D.)
Pharmacist
Pharmacist
Pharmacist
Doctor of Pharmacy (Pharm.D.)
Pharmacist
Career & Practice History
NPI enumerated April 10, 2020.
No changes to the name, practice address, taxonomy or NPI status in this record have been observed in the monthly NPPES data files from April 2020 to August 2026.
NPI Administrative Meta
Other Pharmacists in Greenbrae
Healthcare providers in GreenbraeMore public profiles in California
Directory navigation, in NPI number order.
- Mohsin Mirza, MBBS Internal Medicine - Nephrology · Loma Linda
- Kenny Kumar, MD Student in an Organized Health Care Education/Training Program · French Camp
- Sharon Maslow, RN Registered Nurse · San Luis Obispo
- Alexander Baradei, MD Psychiatry & Neurology - Psychiatry · Stockton
- Marlene Guerrero, APRN, NP-C Nurse Practitioner - Family · Reedley
- Grace Sotelo, MD Urology · Encinitas
- Kelsey Roelofs, MD Ophthalmology - Ophthalmic Plastic and Reconstructive Surgery · Los Angeles
- Talayeh Azarpajouh Dentist - Endodontics · Costa Mesa
- Cody Civiletto, MD Psychiatry & Neurology - Psychiatry · Palo Alto
- Shana Mcclain, MD Internal Medicine · San Francisco
- Courtney Konchan, DO Internal Medicine · San Diego
- Jennifer Kim, MD Internal Medicine - Geriatric Medicine · Encinitas
Mailing Address
330 Bon Air Ctr
Greenbrae, CA 949043017
Phone: 4154619093