Ilaria Mastroserio, PA-C
NPI 1376197590 · Physician Assistant · Walnut Creek, CA
Enrolled with Medicare as Practitioner - Physician Assistant · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Ilaria Mastroserio, PA-C is a Physician Assistant provider in Walnut Creek, CA (NPI 1376197590).
Provider details
- NPI number
- 1376197590
- Entity type
- Individual
- Primary specialty
- Physician AssistantPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- PA-C
- Sex
- Female
- Sole proprietor
- No
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
6 yrs in NPPES registry
- Profile completeness25% of score
83% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
381 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 High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 195 | $146 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 50 | $100 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 50 | $111 |
| Subsequent Hospital Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 25 Minutes99231 | 38 | $46 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 28 | $75 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 8 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Ondansetron Hcl | 23 | 21 |
| Prochlorperazine Maleate | 22 | 18 |
| Lenalidomide | 16 | 12 |
| Pomalidomidebrand: Pomalyst | 15 | — |
| Sulfamethoxazole/Trimethoprimbrand: Sulfamethoxazole-Trimethoprim | 14 | — |
| Lorazepam | 13 | 11 |
| Acyclovir | 13 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$216 across 9 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
- 2019-07-25
- Last updated
- 2024-05-22
- Certified
- 2024-05-22
Frequently asked questions
- What is Ilaria Mastroserio's NPI number?
- Ilaria Mastroserio's National Provider Identifier (NPI) is 1376197590, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Ilaria Mastroserio's specialty?
- Ilaria Mastroserio is listed in the NPPES registry with a primary specialty of Physician Assistant (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Ilaria Mastroserio located?
- Ilaria Mastroserio's practice location on file with NPPES is 177 La Casa Via Ste 390, Walnut Creek, CA 94598-6101.
- What is Ilaria Mastroserio's phone number?
- The practice phone number listed in the NPPES registry for Ilaria Mastroserio is (925) 692-5610.
- Does Ilaria Mastroserio accept Medicare?
- Ilaria Mastroserio is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Ilaria Mastroserio's NPI active?
- Yes — Ilaria Mastroserio's NPI (1376197590) is active in the NPPES registry as of the last update on 2024-05-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.