Katherine Sieu, RN, NP
NPI 1356591085 · Adult Health Nurse Practitioner · Walnut Creek, CA
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Katherine Sieu, RN, NP is a Adult Health Nurse Practitioner provider in Walnut Creek, CA (NPI 1356591085).
Provider details
- NPI number
- 1356591085
- Entity type
- Individual
- Primary specialty
- Adult Health Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- RN, NP
- Sex
- Female
- Sole proprietor
- Yes
- License
- 18369 (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 tenure33% of score
17 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 · 11 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Letrozole | 45 | 12 |
| Hydroxyurea | 32 | — |
| Acyclovir | 28 | — |
| Levothyroxine Sodium | 24 | — |
| Pantoprazole Sodium | 19 | — |
| Tamoxifen Citrate | 17 | — |
| Gabapentin | 16 | — |
| Rivaroxaban |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$305 across 12 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
- 2008-09-30
- Last updated
- 2010-08-27
Frequently asked questions
- What is Katherine Sieu's NPI number?
- Katherine Sieu's National Provider Identifier (NPI) is 1356591085, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Katherine Sieu's specialty?
- Katherine Sieu is listed in the NPPES registry with a primary specialty of Adult Health Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Katherine Sieu located?
- Katherine Sieu's practice location on file with NPPES is 500 Lennon Ln, Walnut Creek, CA 94598-2415.
- What is Katherine Sieu's phone number?
- The practice phone number listed in the NPPES registry for Katherine Sieu is (925) 939-9610.
- Does Katherine Sieu accept Medicare?
- Katherine Sieu is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Katherine Sieu's NPI active?
- Yes — Katherine Sieu's NPI (1356591085) is active in the NPPES registry as of the last update on 2010-08-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.