2026 NPPES data Emergency Medicine Physician NPI 1164603635 M.D.
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GRACE DE GUZMAN, M.D.

Emergency Medicine Physician in BALDWIN PARK, California. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
268
Medicare Part D claims · 126 beneficiaries · Emergency Medicine Physician avg: 352

What the federal data shows

GRACE DE GUZMAN, M.D. filed 268 Medicare Part D claims in 2023 as a Emergency Medicine Physician in BALDWIN PARK, California.

268
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.

GRACE DE GUZMAN, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

268 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)

GRACE DE GUZMAN, M.D. 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 GRACE DE GUZMAN, M.D.?

Quality data not reported

NPI registry status

Active

Issued 11/26/2007

NPI 1164603635

Primary specialty

Emergency Medicine Physician

High-volume

64,398 US NPIs in this specialty

Medicare Part D claims

268 24% 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

Emergency Medicine Physician share within California

1. Emergency Medicine Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Emergency Medicine Physician share within California

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).

GRACE DE GUZMAN, M.D. appears in the CMS NPPES registry as a Emergency Medicine Physician provider holding M.D. credentials at 1011 BALDWIN PARK BLVD, BALDWIN PARK, CA, 91706, with a listed phone of (626) 851-1011. NPI 1164603635 was issued on 11/26/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DE GUZMAN 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 268 prescription claims written by this provider, covering 126 Medicare beneficiaries and totaling roughly $4K in drug spend, with an opioid prescribing rate of 9.7%. 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

1011 BALDWIN PARK BLVD
BALDWIN PARK, CA 91706

Provider Details

NPI 1164603635
Specialty Emergency Medicine Physician
Credentials M.D.
Gender Female
NPI Issued 11/26/2007

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 GRACE DE GUZMAN, M.D.. To verify GRACE DE GUZMAN, M.D.'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.

268
Total Claims
$4K
Total Drug Cost
126
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
309
Total Day Supply
5,537
Generic Drug Cost
$3K
Opioid Claims
26 (9.7% rate)
Antibiotic Claims
62

Patient Demographics

Average Patient Age
73.8 years
Avg HCC Risk Score
1.63
Gender Split
71% female / 29% male
Age Distribution
<65: 12, 65-74: 55, 75-84: 40, 85+: 19

Top Prescribed Drugs (Medicare Part D)

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

What GRACE DE GUZMAN, M.D. 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
Ondansetron Odt
Ondansetron
34
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
16
Cephalexin
12
Albuterol Sulfate Hfa
Albuterol Sulfate
11
Prednisone
11

* 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 GRACE DE GUZMAN, M.D. 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

GRACE DE GUZMAN, M.D.'s 268 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 DE GUZMAN.

Compare Emergency Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is GRACE DE GUZMAN, M.D.'s specialty?
GRACE DE GUZMAN, M.D. specializes in Emergency Medicine Physician and practices in BALDWIN PARK, California. Credentials: M.D..
How much does GRACE DE GUZMAN, M.D. prescribe under Medicare Part D?
In 2023, GRACE DE GUZMAN, M.D. wrote 268 Medicare Part D claims totaling $4K in drug costs for 126 beneficiaries.
Where is GRACE DE GUZMAN, M.D. located?
GRACE DE GUZMAN, M.D. is located at 1011 BALDWIN PARK BLVD, BALDWIN PARK, CA, 91706. Phone: (626) 851-1011.
What is GRACE DE GUZMAN, M.D.'s NPI number?
GRACE DE GUZMAN, M.D.'s National Provider Identifier (NPI) is 1164603635, issued on 11/26/2007.
Does GRACE DE GUZMAN, M.D. prescribe opioids?
Yes, GRACE DE GUZMAN, M.D. had 26 opioid claims in 2023 with an opioid prescribing rate of 9.7%.
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 GRACE DE GUZMAN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, GRACE DE GUZMAN, M.D.'s most frequently prescribed drugs include Ondansetron Odt, Hydrocodone-Acetaminophen, Cephalexin. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does GRACE DE GUZMAN, M.D. accept Medicare?
GRACE DE GUZMAN, M.D. appears in CMS Medicare data with 268 Part D claims and 126 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify GRACE DE GUZMAN, M.D.'s credentials?
GRACE DE GUZMAN, M.D.'s NPI is 1164603635 with credentials M.D.. 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