NPI registry status
Active
2026 NPPES data Neurology Physician NPI 1578503462 MD
Verify on CMS → Chau Chien, MD
Neurology 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 20,467 in Neurology 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
720
Medicare Part D claims · 227 beneficiaries · Neurology Physician avg: 1K
Generic prescribing
97%
generic claims · 3% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
Chau Chien, MD filed 720 Medicare Part D claims in 2024 as a Neurology Physician in San Francisco, California, prescribing 97% generic.
- 720
- Part D claims, 2024
- 97%
- generic prescribing
- ≥70th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about Chau Chien, MD
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1578503462), first enumerated 06/07/2006.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 720 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Practices in an ABMS-board-eligible specialty; board certification not confirmed in federal records.
- State context
State board disciplinary context
California statewide board action statistics are published annually — these figures describe aggregate state activity, not Chau Chien, MD's individual license status. Verify directly with the state medical board.
Source: MBC annual report 2023
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1578503462 · Neurology Physician
NPI-10 · ENUM-LEGACY · TAX-MID · RX-LIGHT · BOOK-LIGHT · PHOTO-ENUM
- NPI-10 1578503462
- ENUM-LEGACY 2006
- TAX-MID 20K Neurology Physician
- RX-LIGHT 720
- BOOK-LIGHT 2,160 in California
- PHOTO-ENUM Vernon Cooper, M.D. · 2006
Chau Chien, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
720 ≥ 70th percentile 70% of 1,416,883 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
◑
Board-eligible specialty (heuristic, not verified)
Chau Chien, 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 Chau Chien, MD?
Quality data not reportedPrimary specialty
Neurology Physician
Medicare Part D claims
720 47% vs specialty avg
Specialty distribution in California
How Neurology 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 Neurology 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).
Practice Address
Provider Details
| NPI | 1578503462 |
|---|---|
| Specialty | Neurology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 06/07/2006 |
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 Chau Chien, MD. To verify Chau Chien, 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 · Generic-heavy
Chau Chien, MD - brand share 3.0%
Neurology Physician average
3% brand-name claims vs 97% generic, on 720 2024 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 2024.
720
Total Claims
$40K
Total Drug Cost
227
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,976.633
- Total Day Supply
- 59,033
- Brand vs Generic
- 3% brand / 97% generic
- Brand Drug Cost
- $12K
- Generic Drug Cost
- $28K
Patient Demographics
- Average Patient Age
- 80.3 years
- Avg HCC Risk Score
- 1.50
- Gender Split
- 60% female / 40% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What Chau Chien, MD prescribes most
Top Medicare Part D drugs by claim count, 2024
- Memantine Hcl
Memantine Hcl
245 claims
- Gabapentin
Gabapentin
99 claims
- Carbidopa-Levodopa… 84
Carbidopa-Levodopa Er
84 claims
- Levetiracetam 45
Levetiracetam
45 claims
- Carbidopa-Levodopa 24
Carbidopa-Levodopa
24 claims
- Selegiline Hcl 22
Selegiline Hcl
22 claims
- Donepezil Hcl 20
Donepezil Hcl
20 claims
- Propranolol Hcl 19
Propranolol Hcl
19 claims
| Drug | Claims |
|---|---|
| Memantine Hcl | 245 |
| Gabapentin | 99 |
| Carbidopa-Levodopa Er Carbidopa/Levodopa | 84 |
| Levetiracetam | 45 |
| Carbidopa-Levodopa Carbidopa/Levodopa | 24 |
| Selegiline Hcl | 22 |
| Donepezil Hcl | 20 |
| Propranolol Hcl | 19 |
| Quetiapine Fumarate | 17 |
| Trazodone Hcl | 16 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Neurology Physician Overview
How Chau Chien, MD fits within the Neurology Physician landscape nationally.
20,467
Neurology Physician Providers in US
54
States with Neurology Physician
1,356
Avg Claims per Provider
Chau Chien, MD's 720 claims are below the specialty average of 1,356.
Nationwide Neurology Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Chien, both outside California so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2006)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Neurology Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Chien.
One of 2,160 Neurology Physician providers enrolled in California, 5 are shown here.
Dr. Venkat Raghav Aachi
MD
Thousand Oaks, CA
Dr. John Aalbers
M.D.
San Diego, CA
Dr. Puya Abbassi
D.O.
San Jose, CA
Ahmed Abdelhak
MB CHB
San Francisco, CA
Dr. Hadi Abou El Hassan
MD
Los Angeles, CA
Compare Neurology Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Chau Chien, MD's specialty? ▼
Chau Chien, MD specializes in Neurology Physician and practices in San Francisco, California. Credentials: MD.
How much does Chau Chien, MD prescribe under Medicare Part D? ▼
In 2024, Chau Chien, MD wrote 720 Medicare Part D claims totaling $40K in drug costs for 227 beneficiaries.
Where is Chau Chien, MD located? ▼
Chau Chien, MD is located at 3115 GEARY BLVD, San Francisco, CA, 94118. Phone: (415) 981-6013.
What is Chau Chien, MD's NPI number? ▼
Chau Chien, MD's National Provider Identifier (NPI) is 1578503462, issued on 06/07/2006.
Does Chau Chien, MD prescribe more brand-name or generic drugs? ▼
Chau Chien, MD's prescribing is 3% brand-name and 97% generic drugs by claim count, with $12K in brand drug costs.
How many Neurology Physician providers are there in the US? ▼
There are 20,467 Neurology Physician providers across 54 states in the US. The average Neurology Physician provider writes 1,356 Medicare Part D claims per year.
What drugs does Chau Chien, MD prescribe most often? ▼
Based on 2024 Medicare Part D data, Chau Chien, MD's most frequently prescribed drugs include Memantine Hcl, Gabapentin, Carbidopa-Levodopa Er. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Chau Chien, MD accept Medicare? ▼
Chau Chien, MD appears in CMS Medicare data with 720 Part D claims and 227 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Chau Chien, MD's credentials? ▼
Chau Chien, MD's NPI is 1578503462 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 (2024). 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 August 2026 (NPPES) / 2024 (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
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of August 2026.