Mallory Callahan, NP
NPI 1528778214 · Nurse Practitioner · Stanford, CA
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mallory Callahan, NP is a Nurse Practitioner provider in Stanford, CA (NPI 1528778214).
Provider details
- NPI number
- 1528778214
- Entity type
- Individual
- Primary specialty
- Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- NP
- Sex
- Female
- Sole proprietor
- No
- License
- 95023364 (CA)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
3 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
358 Medicare services, 2024 (ranked within specialty)
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 methodology.
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 Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 120 | $86 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 93 | $124 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 77 | $169 |
| Subsequent Hospital Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 25 Minutes99231 | 43 | $47 |
| Established Patient Office Or Other Outpatient Visit With Straightforward Medical Decision Making, If Using Time, 10 Minutes Or More99212 | 25 | $56 |
Typical Medicare-allowed amounts for these services range $47–$169 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, 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 · 10 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Omeprazole | 114 | 50 |
| Pantoprazole Sodium | 59 | 26 |
| Linaclotidebrand: Linzess | 40 | 16 |
| Prucalopride Succinatebrand: Motegrity | 22 | — |
| Ursodiol | 18 | — |
| Famotidine | 15 | — |
| Dexlansoprazolebrand: Dexlansoprazole Dr | 13 | — |
Practice location
Mailing address
Additional practice locations (1)
- 420 Broadway StRedwood City, CA 94063-3132Phone: (650) 736-5555
Registry dates
- Enumerated
- 2022-12-02
- Last updated
- 2025-12-30
- Certified
- 2025-12-30
Frequently asked questions
- What is Mallory Callahan's NPI number?
- Mallory Callahan's National Provider Identifier (NPI) is 1528778214, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mallory Callahan's specialty?
- Mallory Callahan is listed in the NPPES registry with a primary specialty of Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Mallory Callahan located?
- Mallory Callahan's practice location on file with NPPES is 300 Pasteur Dr, Stanford, CA 94305-2200.
- What is Mallory Callahan's phone number?
- The practice phone number listed in the NPPES registry for Mallory Callahan is (650) 723-4000.
- Does Mallory Callahan accept Medicare?
- Mallory Callahan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mallory Callahan's NPI active?
- Yes — Mallory Callahan's NPI (1528778214) is active in the NPPES registry as of the last update on 2025-12-30.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.