2026 NPPES data Dermatology Physician NPI 1841386489 M.D., PH.D.
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TATIANA GRZESZKIEWICZ, M.D., PH.D.

Dermatology Physician in FREMONT, 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
2K
Medicare Part D claims · 540 beneficiaries · Dermatology Physician avg: 729
Generic prescribing
93%
generic claims · 7% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$125
1 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

TATIANA GRZESZKIEWICZ, M.D., PH.D. filed 1,606 Medicare Part D claims in 2023 as a Dermatology Physician in FREMONT, California, prescribing 93% generic.

2K
Part D claims, 2023
93%
generic prescribing
Likely
board-certified (heuristic)

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.

TATIANA GRZESZKIEWICZ, M.D., PH.D.'s Medicare Part D volume vs every U.S. prescriber

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

1,606 Top 18% higher than 82% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). This entry sits in this band. 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 certification likely (heuristic — not verified)

TATIANA GRZESZKIEWICZ, M.D., PH.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about TATIANA GRZESZKIEWICZ, M.D., PH.D.?

Quality data not reported

NPI registry status

Active

Issued 10/04/2006

NPI 1841386489

Primary specialty

Dermatology Physician

Mid-sized

14,610 US NPIs in this specialty

Medicare Part D claims

1,606 120% vs specialty avg

2023 prescription claims

Specialty avg: 729

Specialty distribution in California

How Dermatology Physician compares to other specialties among California providers

California providers

Dermatology Physician share within California

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

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Dermatology 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).

TATIANA GRZESZKIEWICZ, M.D., PH.D. appears in the CMS NPPES registry as a Dermatology Physician provider holding M.D., PH.D. credentials at 3200 KEARNEY ST, FREMONT, CA, 94538, with a listed phone of (510) 490-1222. NPI 1841386489 was issued on 10/04/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what GRZESZKIEWICZ 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 1,606 prescription claims written by this provider, covering 540 Medicare beneficiaries and totaling roughly $472K in drug spend, split 7% brand-name and 93% generic by claim count. 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.

Dermatology Physician is a mid-sized specialty nationwide, with 14,610 enrolled providers across 53 states and an average of 729 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

3200 KEARNEY ST
FREMONT, CA 94538

Provider Details

NPI 1841386489
Specialty Dermatology Physician
Credentials M.D., PH.D.
Gender Female
NPI Issued 10/04/2006

Hospital and facility affiliations

Facilities where TATIANA GRZESZKIEWICZ, M.D., PH.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

SUTTER BAY MEDICAL FOUNDATION
SOQUEL, CA

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Industry payments received (2024) — CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for TATIANA GRZESZKIEWICZ, M.D., PH.D.. Source: openpaymentsdata.cms.gov.

Total received

$125

Largest payer

Lilly USA, LLC

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

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 TATIANA GRZESZKIEWICZ, M.D., PH.D.. To verify TATIANA GRZESZKIEWICZ, M.D., PH.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.

Brand vs generic prescribing mix · Generic-heavy

TATIANA GRZESZKIEWICZ, M.D., PH.D. — brand share 7.0%
Specialty average (est.)

7% brand-name claims vs 93% generic, on 1,606 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.

1,606
Total Claims
$472K
Total Drug Cost
540
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,872
Total Day Supply
51,292
Brand vs Generic
7% brand / 93% generic
Brand Drug Cost
$386K
Generic Drug Cost
$86K
Antibiotic Claims
71

Patient Demographics

Average Patient Age
73.6 years
Avg HCC Risk Score
1.03
Gender Split
55% female / 45% male
Age Distribution
<65: 37, 65-74: 256, 75-84: 191, 85+: 56

Top Prescribed Drugs (Medicare Part D)

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

What TATIANA GRZESZKIEWICZ, M.D., PH.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
Triamcinolone Acetonide
253
Betamethasone Diprop Augmented
Betamethasone/Propylene Glyc
238
Doxycycline Hyclate
96
Fluorouracil
77
Metronidazole
74
Ketoconazole
71
Fluocinonide
67
Clobetasol Propionate
56
Tacrolimus
49
Hydrocortisone
47

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

Dermatology Physician Overview

How TATIANA GRZESZKIEWICZ, M.D., PH.D. fits within the Dermatology Physician landscape nationally.

14,610
Dermatology Physician Providers in US
53
States with Dermatology Physician
729
Avg Claims per Provider

TATIANA GRZESZKIEWICZ, M.D., PH.D.'s 1,606 claims are above the specialty average of 729.

Nearby Dermatology Physician Providers in California

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

Compare Dermatology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is TATIANA GRZESZKIEWICZ, M.D., PH.D.'s specialty?
TATIANA GRZESZKIEWICZ, M.D., PH.D. specializes in Dermatology Physician and practices in FREMONT, California. Credentials: M.D., PH.D..
How much does TATIANA GRZESZKIEWICZ, M.D., PH.D. prescribe under Medicare Part D?
In 2023, TATIANA GRZESZKIEWICZ, M.D., PH.D. wrote 1,606 Medicare Part D claims totaling $472K in drug costs for 540 beneficiaries.
Where is TATIANA GRZESZKIEWICZ, M.D., PH.D. located?
TATIANA GRZESZKIEWICZ, M.D., PH.D. is located at 3200 KEARNEY ST, FREMONT, CA, 94538. Phone: (510) 490-1222.
What is TATIANA GRZESZKIEWICZ, M.D., PH.D.'s NPI number?
TATIANA GRZESZKIEWICZ, M.D., PH.D.'s National Provider Identifier (NPI) is 1841386489, issued on 10/04/2006.
Does TATIANA GRZESZKIEWICZ, M.D., PH.D. prescribe more brand-name or generic drugs?
TATIANA GRZESZKIEWICZ, M.D., PH.D.'s prescribing is 7% brand-name and 93% generic drugs by claim count, with $386K in brand drug costs.
How many Dermatology Physician providers are there in the US?
There are 14,610 Dermatology Physician providers across 53 states in the US. The average Dermatology Physician provider writes 729 Medicare Part D claims per year.
What drugs does TATIANA GRZESZKIEWICZ, M.D., PH.D. prescribe most often?
Based on 2023 Medicare Part D data, TATIANA GRZESZKIEWICZ, M.D., PH.D.'s most frequently prescribed drugs include Triamcinolone Acetonide, Betamethasone Diprop Augmented, Doxycycline Hyclate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does TATIANA GRZESZKIEWICZ, M.D., PH.D. accept Medicare?
TATIANA GRZESZKIEWICZ, M.D., PH.D. appears in CMS Medicare data with 1,606 Part D claims and 540 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify TATIANA GRZESZKIEWICZ, M.D., PH.D.'s credentials?
TATIANA GRZESZKIEWICZ, M.D., PH.D.'s NPI is 1841386489 with credentials M.D., PH.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