Charlaine Williamson, NP
NPI 1932408960 · Family Nurse Practitioner · Rancho Cucamonga, CA
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Charlaine Williamson, NP is a Family Nurse Practitioner provider in Rancho Cucamonga, CA (NPI 1932408960).
Provider details
- NPI number
- 1932408960
- Entity type
- Individual
- Primary specialty
- Family Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- NP
- Sex
- Female
- Sole proprietor
- No
- License
- 19923 (CA)
Specialties & taxonomies
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
15 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
726 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 | 411 | $117 |
| Continuous Monitoring of Blood Sugar Level in Tissue Fluid Using Sensor Under Skin With Interpretation and Report95251 | 103 | $30 |
| Hemoglobin A1c Level83036 | 60 | $10 |
| Office Or Other Outpatient Visit for the Evaluation and Management of Established Patient That May Not Require Presence of Healthcare Professional99211 | 35 | $22 |
| Telephone Medical Discussion With Physician, 11-20 Minutes99442 | 30 | $84 |
| Telephone Medical Discussion With Physician, 21-30 Minutes99443 | 26 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 41 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Semaglutidebrand: Ozempic | 259 | 78 |
| Levothyroxine Sodium | 228 | 76 |
| Insulin Glargine,hum.rec.anlogbrand: Lantus Solostar | 142 | 54 |
| Tirzepatidebrand: Mounjaro | 114 | 29 |
| Empagliflozinbrand: Jardiance | 110 | 37 |
| Pen Needle, Diabeticbrand: Nano 2nd Gen Pen Needle | 104 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$2,660 across 102 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
Additional practice locations (1)
- 100 E Valencia Mesa Dr Ste 105Fullerton, CA 92835-3816Phone: (714) 446-5640
Registry dates
- Enumerated
- 2011-03-16
- Last updated
- 2021-04-13
- Certified
- 2021-04-13
Frequently asked questions
- What is Charlaine Williamson's NPI number?
- Charlaine Williamson's National Provider Identifier (NPI) is 1932408960, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Charlaine Williamson's specialty?
- Charlaine Williamson is listed in the NPPES registry with a primary specialty of Family Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Charlaine Williamson located?
- Charlaine Williamson's practice location on file with NPPES is 9170 Haven Ave Ste 120, Rancho Cucamonga, CA 91730-5416.
- What is Charlaine Williamson's phone number?
- The practice phone number listed in the NPPES registry for Charlaine Williamson is (909) 476-8700.
- Does Charlaine Williamson accept Medicare?
- Charlaine Williamson is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Charlaine Williamson's NPI active?
- Yes — Charlaine Williamson's NPI (1932408960) is active in the NPPES registry as of the last update on 2021-04-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.