NPI registry status
Active
2026 NPPES data Hematology & Oncology Physician NPI 1871766576 MD
Verify on CMS → Andrea Harzstark, MD
Hematology & Oncology Physician in San Francisco, California.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 11,215 in Hematology & Oncology Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
1K
Medicare Part D claims · 128 beneficiaries · Hematology & Oncology Physician avg: 847
Generic prescribing
79%
generic claims · 21% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Andrea Harzstark, MD filed 1,023 Medicare Part D claims in 2023 as a Hematology & Oncology Physician in San Francisco, California, prescribing 79% generic.
- 1K
- Part D claims, 2023
- 79%
- generic prescribing
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Andrea Harzstark, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
1,023 Top 24% higher than 76% of 1,370,886 prescribers
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Medicare Part D Prescriber Public Use File · 2023
◑
Board-eligible specialty (heuristic, not verified)
Andrea Harzstark, MD practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Andrea Harzstark, MD?
Quality data not reportedPrimary specialty
Hematology & Oncology Physician
Medicare Part D claims
1,023 21% vs specialty avg
Specialty distribution in California
How Hematology & Oncology Physician compares to other specialties among California providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Hematology & Oncology Physician. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Andrea Harzstark, MD appears in the CMS NPPES registry as a Hematology & Oncology Physician provider holding MD credentials at 1600 DIVISADERO ST, San Francisco, CA, 94143, with a listed phone of (415) 353-7171. NPI 1871766576 was issued on 04/02/2008.
Medicare Part D records for calendar year 2023 show 1,023 prescription claims written by this provider, covering 128 Medicare beneficiaries and totaling roughly $2.9 million in drug spend, split 21% brand-name and 79% generic by claim count, with an opioid prescribing rate of 1.9%.
Hematology & Oncology Physician is a mid-sized specialty nationwide, with 11,215 enrolled providers across 54 states and an average of 847 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline.
Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist, always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1871766576 |
|---|---|
| Specialty | Hematology & Oncology Physician |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 04/02/2008 |
License & disciplinary context - California MBC 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~150K California medical licensees in 2023 - they are NOT specific to Andrea Harzstark, MD. To verify Andrea Harzstark, MD's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases
MBC publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Typical
Andrea Harzstark, MD - brand share 21.0%
Hematology & Oncology Physician average
21% brand-name claims vs 79% generic, on 1,023 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
1,023
Total Claims
$2.9M
Total Drug Cost
128
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,936
- Total Day Supply
- 56,230
- Brand vs Generic
- 21% brand / 79% generic
- Brand Drug Cost
- $2.8M
- Generic Drug Cost
- $77K
- Opioid Claims
- 19 (1.9% rate)
Patient Demographics
- Average Patient Age
- 75.3 years
- Avg HCC Risk Score
- 2.02
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Andrea Harzstark, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Abiraterone Acetate
Abiraterone Acetate
274 claims
- Prednisone
Prednisone
177 claims
- Xtandi 74
Xtandi
74 claims
- Nubeqa 49
Nubeqa
49 claims
- Bicalutamide 40
Bicalutamide
40 claims
- Alendronate Sodium 35
Alendronate Sodium
35 claims
- Dexamethasone 26
Dexamethasone
26 claims
- Gabapentin 26
Gabapentin
26 claims
| Drug | Claims |
|---|---|
| Abiraterone Acetate | 274 |
| Prednisone | 177 |
| Xtandi Enzalutamide | 74 |
| Nubeqa Darolutamide | 49 |
| Bicalutamide | 40 |
| Alendronate Sodium | 35 |
| Dexamethasone | 26 |
| Gabapentin | 26 |
| Potassium Chloride | 20 |
| Prochlorperazine Maleate | 19 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Hematology & Oncology Physician Overview
How Andrea Harzstark, MD fits within the Hematology & Oncology Physician landscape nationally.
11,215
Hematology & Oncology Physician Providers in US
54
States with Hematology & Oncology Physician
847
Avg Claims per Provider
Andrea Harzstark, MD's 1,023 claims are above the specialty average of 847.
Nearby Hematology & Oncology Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Harzstark.
Dr. Mark Abate
M.D.
Santa Barbara, CA
Dr. Iman Abdalla
MD
Los Angeles, CA
Dr. Nihal Abdulla
MD
Los Alamitos, CA
Dr. Oyewale Abidoye
M.D.
La Jolla, CA
Dr. Mohamad Adada
M.D., PHD
Roseville, CA
Compare Hematology & Oncology Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the California medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Hematology & Oncology Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Andrea Harzstark, MD's specialty? ▼
Andrea Harzstark, MD specializes in Hematology & Oncology Physician and practices in San Francisco, California. Credentials: MD.
How much does Andrea Harzstark, MD prescribe under Medicare Part D? ▼
In 2023, Andrea Harzstark, MD wrote 1,023 Medicare Part D claims totaling $2.9M in drug costs for 128 beneficiaries.
Where is Andrea Harzstark, MD located? ▼
Andrea Harzstark, MD is located at 1600 DIVISADERO ST, San Francisco, CA, 94143. Phone: (415) 353-7171.
What is Andrea Harzstark, MD's NPI number? ▼
Andrea Harzstark, MD's National Provider Identifier (NPI) is 1871766576, issued on 04/02/2008.
Does Andrea Harzstark, MD prescribe more brand-name or generic drugs? ▼
Andrea Harzstark, MD's prescribing is 21% brand-name and 79% generic drugs by claim count, with $2.8M in brand drug costs.
Does Andrea Harzstark, MD prescribe opioids? ▼
Yes, Andrea Harzstark, MD had 19 opioid claims in 2023 with an opioid prescribing rate of 1.9%.
How many Hematology & Oncology Physician providers are there in the US? ▼
There are 11,215 Hematology & Oncology Physician providers across 54 states in the US. The average Hematology & Oncology Physician provider writes 847 Medicare Part D claims per year.
What drugs does Andrea Harzstark, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Andrea Harzstark, MD's most frequently prescribed drugs include Abiraterone Acetate, Prednisone, Xtandi. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Andrea Harzstark, MD accept Medicare? ▼
Andrea Harzstark, MD appears in CMS Medicare data with 1,023 Part D claims and 128 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Andrea Harzstark, MD's credentials? ▼
Andrea Harzstark, MD's NPI is 1871766576 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Compiled from official public sources by the PlainDoctor editorial team.