2026 NPPES data Emergency Medicine Physician NPI 1477627784 DO
Verify on CMS →

Harold Woo, DO

Emergency Medicine Physician in Walnut Creek, 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 64,398 in Emergency Medicine 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
256
Medicare Part D claims · 153 beneficiaries · Emergency Medicine Physician avg: 352
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Harold Woo, DO filed 256 Medicare Part D claims in 2023 as a Emergency Medicine Physician in Walnut Creek, California.

256
Part D claims, 2023

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.

Harold Woo, DO's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

256 49th percentile higher than 49% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). This entry sits in this band. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

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)

Harold Woo, DO 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 Harold Woo, DO?

Quality data not reported

NPI registry status

Active

Issued 11/20/2006

NPI 1477627784

Primary specialty

Emergency Medicine Physician

High-volume

64,398 US NPIs in this specialty

Medicare Part D claims

256 27% vs specialty avg

2023 prescription claims

Specialty avg: 352

Specialty distribution in California

How Emergency Medicine Physician compares to other specialties among California providers

California providers

Largest specialties in California (% of in-state providers)

Behavior Technician — 17.3%Behavior Technician17.3%Marriage & Family Therapist — 5.5%Marriage & Family Therapist5.5%Student in an Organized Health Care Education/Training Program — 5%Student in an Organized Health Care Education/Training Program5%Mental Health Counselor — 3.9%Mental Health Counselor3.9%Pharmacist — 3.5%Pharmacist3.5%Clinical Social Worker — 3.1%Clinical Social Worker3.1%Emergency Medicine Physician — 0.7%Emergency Medicine Physician0.7%
Largest specialties in California (% of in-state providers)

Specialty board-certification context

Estimated specialty board-certified rate — Emergency Medicine Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Emergency Medicine Physician ABMS/AOA estimate

Est. board-certified rate (Emergency Medicine Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Emergency Medicine Physician) — ABMS / AOA estimate

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).

Harold Woo, DO appears in the CMS NPPES registry as a Emergency Medicine Physician provider holding DO credentials at 324 CONIFER CT, Walnut Creek, CA, 94598, with a listed phone of (925) 708-2038. NPI 1477627784 was issued on 11/20/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Woo most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 256 prescription claims written by this provider, covering 153 Medicare beneficiaries and totaling roughly $4K in drug spend. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Emergency Medicine Physician is a high-volume specialty nationwide, with 64,398 enrolled providers across 56 states and an average of 352 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

324 CONIFER CT
Walnut Creek, CA 94598

Provider Details

NPI 1477627784
Specialty Emergency Medicine Physician
Credentials DO
Gender Male
NPI Issued 11/20/2006

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 Harold Woo, DO. To verify Harold Woo, DO'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.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

256
Total Claims
$4K
Total Drug Cost
153
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
256
Total Day Supply
2,383
Generic Drug Cost
$2K
Antibiotic Claims
61

Patient Demographics

Average Patient Age
66.7 years
Avg HCC Risk Score
1.36
Gender Split
67% female / 33% male
Age Distribution
<65: 43, 65-74: 69, 75-84: N/A, 85+: N/A

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What Harold Woo, DO prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Ibuprofen
73
Cephalexin
29
Prednisone
16
Cyclobenzaprine Hcl
15
Dicyclomine Hcl
15

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Emergency Medicine Physician Overview

How Harold Woo, DO fits within the Emergency Medicine Physician landscape nationally.

64,398
Emergency Medicine Physician Providers in US
56
States with Emergency Medicine Physician
352
Avg Claims per Provider

Harold Woo, DO's 256 claims are below the specialty average of 352.

Nearby Emergency Medicine Physician Providers in California

Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Woo.

Compare Emergency Medicine 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 Emergency Medicine 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.

Frequently Asked Questions

What is Harold Woo, DO's specialty?
Harold Woo, DO specializes in Emergency Medicine Physician and practices in Walnut Creek, California. Credentials: DO.
How much does Harold Woo, DO prescribe under Medicare Part D?
In 2023, Harold Woo, DO wrote 256 Medicare Part D claims totaling $4K in drug costs for 153 beneficiaries.
Where is Harold Woo, DO located?
Harold Woo, DO is located at 324 CONIFER CT, Walnut Creek, CA, 94598. Phone: (925) 708-2038.
What is Harold Woo, DO's NPI number?
Harold Woo, DO's National Provider Identifier (NPI) is 1477627784, issued on 11/20/2006.
How many Emergency Medicine Physician providers are there in the US?
There are 64,398 Emergency Medicine Physician providers across 56 states in the US. The average Emergency Medicine Physician provider writes 352 Medicare Part D claims per year.
What drugs does Harold Woo, DO prescribe most often?
Based on 2023 Medicare Part D data, Harold Woo, DO's most frequently prescribed drugs include Ibuprofen, Cephalexin, Prednisone. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Harold Woo, DO accept Medicare?
Harold Woo, DO appears in CMS Medicare data with 256 Part D claims and 153 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Harold Woo, DO's credentials?
Harold Woo, DO's NPI is 1477627784 with credentials DO. 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

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.