Tammy Chen, NURSE PRACTITIONER
NPI 1255792875 · Adult Health Nurse Practitioner · Fullerton, CA
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Tammy Chen, NURSE PRACTITIONER is a Adult Health Nurse Practitioner provider in Fullerton, CA (NPI 1255792875).
Provider details
- NPI number
- 1255792875
- Entity type
- Individual
- Primary specialty
- Adult Health Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- NURSE PRACTITIONER
- Sex
- Female
- Sole proprietor
- Yes
- License
- NP95003688 (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
10 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
141 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 | 57 | $118 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 48 | $84 |
| Telephone Medical Discussion With Physician, 11-20 Minutes99442 | 36 | $84 |
Typical Medicare-allowed amounts for these services range $84–$118 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 16 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 456 | 80 |
| Gabapentin | 277 | 66 |
| Tizanidine Hcl | 178 | 47 |
| Tramadol Hcl | 126 | 30 |
| Pregabalin | 122 | 31 |
| Cyclobenzaprine Hcl | 87 | 14 |
| Diclofenac Sodium | 86 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$16 across 1 record (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
- 2016-03-09
- Last updated
- 2018-12-19
Frequently asked questions
- What is Tammy Chen's NPI number?
- Tammy Chen's National Provider Identifier (NPI) is 1255792875, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Tammy Chen's specialty?
- Tammy Chen is listed in the NPPES registry with a primary specialty of Adult Health Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Tammy Chen located?
- Tammy Chen's practice location on file with NPPES is 150 Laguna Rd Ste a, Fullerton, CA 92835-3614.
- What is Tammy Chen's phone number?
- The practice phone number listed in the NPPES registry for Tammy Chen is (714) 525-8822.
- Does Tammy Chen accept Medicare?
- Tammy Chen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Tammy Chen's NPI active?
- Yes — Tammy Chen's NPI (1255792875) is active in the NPPES registry as of the last update on 2018-12-19.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.