Tomoko Williams, MSN, RN, FNP-C
NPI 1255896262 · Family Nurse Practitioner · Irvine, CA
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Tomoko Williams, MSN, RN, FNP-C is a Family Nurse Practitioner provider in Irvine, CA (NPI 1255896262).
Provider details
- NPI number
- 1255896262
- Entity type
- Individual
- Primary specialty
- Family Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- MSN, RN, FNP-C
- Sex
- Female
- Sole proprietor
- No
- License
- AP140322 (TX)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
7 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
1,291 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 388 | $104 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 186 | $9 |
| Complete Blood Cell Count (red Cells, White Blood Cell, Platelets), Automated Test and Automated Differential White Blood Cell Count85025 | 140 | $8 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 100 | $146 |
| Blood Test, Comprehensive Group of Blood Chemicals80053 | 84 | $10 |
| Magnesium Level83735 | 53 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 10 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Ondansetronbrand: Ondansetron Odt | 99 | 67 |
| Prochlorperazine Maleate | 58 | 53 |
| Anastrozole | 35 | — |
| Lidocaine/Prilocainebrand: Lidocaine-Prilocaine | 35 | 26 |
| Gabapentin | 33 | — |
| Famotidine | 26 | 11 |
| Apixabanbrand: Eliquis | 25 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,548 across 67 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2019-02-04
- Last updated
- 2026-02-06
- Certified
- 2026-02-06
Frequently asked questions
- What is Tomoko Williams's NPI number?
- Tomoko Williams's National Provider Identifier (NPI) is 1255896262, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Tomoko Williams's specialty?
- Tomoko Williams is listed in the NPPES registry with a primary specialty of Family Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Tomoko Williams located?
- Tomoko Williams's practice location on file with NPPES is 1000 Fivepoint, Irvine, CA 92618-2621.
- What is Tomoko Williams's phone number?
- The practice phone number listed in the NPPES registry for Tomoko Williams is (800) 826-4673.
- Does Tomoko Williams accept Medicare?
- Tomoko Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Tomoko Williams's NPI active?
- Yes — Tomoko Williams's NPI (1255896262) is active in the NPPES registry as of the last update on 2026-02-06.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.