Cleo Tsolakoglou-Williams, M.D
NPI 1538243126 · Family Medicine Physician · Pasadena, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Cleo Tsolakoglou-Williams, M.D is a Family Medicine Physician provider in Pasadena, CA (NPI 1538243126).
Provider details
- NPI number
- 1538243126
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D
- Sex
- Female
- Sole proprietor
- Yes
- License
- A52191 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
19 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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 methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 7 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Semaglutidebrand: Ozempic | 24 | — |
| Levothyroxine Sodium | 20 | — |
| Rosuvastatin Calcium | 16 | — |
| Atorvastatin Calcium | 16 | 11 |
| Tamsulosin Hcl | 14 | — |
| Amlodipine Besylate | 12 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$522 across 4 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
- 2006-10-24
- Last updated
- 2007-07-09
Frequently asked questions
- What is Cleo Tsolakoglou-Williams's NPI number?
- Cleo Tsolakoglou-Williams's National Provider Identifier (NPI) is 1538243126, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Cleo Tsolakoglou-Williams's specialty?
- Cleo Tsolakoglou-Williams is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Cleo Tsolakoglou-Williams located?
- Cleo Tsolakoglou-Williams's practice location on file with NPPES is 960 E Green St, Pasadena, CA 91106-2401.
- What is Cleo Tsolakoglou-Williams's phone number?
- The practice phone number listed in the NPPES registry for Cleo Tsolakoglou-Williams is (626) 577-4455.
- Does Cleo Tsolakoglou-Williams accept Medicare?
- Cleo Tsolakoglou-Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Cleo Tsolakoglou-Williams's NPI active?
- Yes — Cleo Tsolakoglou-Williams's NPI (1538243126) is active in the NPPES registry as of the last update on 2007-07-09.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.