NPI registry status
Active
2026 NPPES data Obstetrics & Gynecology Physician NPI 1013114719 MD
Verify on CMS → Vasiliki Tatsis, MD
Obstetrics & Gynecology Physician in Fullerton, 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 44,326 in Obstetrics & Gynecology 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.
What the federal data shows
Vasiliki Tatsis, MD is an Obstetrics & Gynecology Physician in Fullerton, California, listed in the federal CMS National Provider Identifier registry.
- Likely
- board-certified (heuristic)
- #37
- Obstetrics & Gynecology Physician rank among California specialties
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.
CMS NPPES provider registry desk
NPI 1013114719 · Obstetrics & Gynecology Physician
NPI-10 · ENUM-MID · TAX-MID · RX-NONE · BOOK-LIGHT · PHOTO-ENUM
- NPI-10 1013114719
- ENUM-MID 2007
- TAX-MID 44K Obstetrics &
- RX-NONE No Part D
- BOOK-LIGHT 4,943 in California
- PHOTO-ENUM Clark Andelin · 2007
✓
Board certification likely (heuristic, not verified)
Vasiliki Tatsis, MD 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 Vasiliki Tatsis, MD?
Quality data not reportedPrimary specialty
Obstetrics & Gynecology Physician
Specialty distribution in California
How Obstetrics & Gynecology 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 Obstetrics & Gynecology 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 | 1013114719 |
|---|---|
| Specialty | Obstetrics & Gynecology Physician |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 06/27/2007 |
Hospital and facility affiliations
Facilities where Vasiliki Tatsis, MD 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.
Ucsf Medical Group Business Services
San Francisco, 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).
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 Vasiliki Tatsis, MD. To verify Vasiliki Tatsis, 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.
Obstetrics & Gynecology Physician Overview
How Vasiliki Tatsis, MD fits within the Obstetrics & Gynecology Physician landscape nationally.
44,326
Obstetrics & Gynecology Physician Providers in US
56
States with Obstetrics & Gynecology Physician
179
Avg Claims per Provider
Nationwide Obstetrics & Gynecology Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Tatsis, both outside California so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2007)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Obstetrics & Gynecology Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Tatsis.
One of 4,943 Obstetrics & Gynecology Physician providers enrolled in California, 5 are shown here.
Dr. Ingrid Aalami
MD
San Jose, CA
Dr. Avisa Abaian- Eagar
M.D.
Orange, CA
Dr. Derek Abbassi
MD
Walnut Creek, CA
Dr. Nicole Abell
DO
Ventura, CA
Zachary Abelson
Los Angeles, CA
Compare Obstetrics & Gynecology Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Vasiliki Tatsis, MD's specialty? ▼
Vasiliki Tatsis, MD specializes in Obstetrics & Gynecology Physician and practices in Fullerton, California. Credentials: MD.
Where is Vasiliki Tatsis, MD located? ▼
Vasiliki Tatsis, MD is located at 2262 N STATE COLLEGE BLVD, Fullerton, CA, 92831. Phone: (714) 990-2900.
What is Vasiliki Tatsis, MD's NPI number? ▼
Vasiliki Tatsis, MD's National Provider Identifier (NPI) is 1013114719, issued on 06/27/2007.
How many Obstetrics & Gynecology Physician providers are there in the US? ▼
There are 44,326 Obstetrics & Gynecology Physician providers across 56 states in the US. The average Obstetrics & Gynecology Physician provider writes 179 Medicare Part D claims per year.
Does Vasiliki Tatsis, MD accept Medicare? ▼
Vasiliki Tatsis, MD appears in CMS Medicare data. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Vasiliki Tatsis, MD's credentials? ▼
Vasiliki Tatsis, MD's NPI is 1013114719 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.
- 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
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 May 2026.