Marian Callanan, CNS
NPI 1265484984 · Clinical Nurse Specialist · Stanford, CA
Enrolled with Medicare as Practitioner - Certified Clinical Nurse Specialist (cns) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Marian Callanan, CNS is a Clinical Nurse Specialist provider in Stanford, CA (NPI 1265484984).
Provider details
- NPI number
- 1265484984
- Entity type
- Individual
- Primary specialty
- Clinical Nurse SpecialistPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- CNS
- Sex
- Female
- Sole proprietor
- Yes
- License
- 572 (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 tenure28% of score
20 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
92 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 Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 32 | $132 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 29 | $92 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 19 | $94 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 12 | $64 |
Typical Medicare-allowed amounts for these services range $64–$132 (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.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-17
- Last updated
- 2023-07-05
- Certified
- 2023-07-05
Frequently asked questions
- What is Marian Callanan's NPI number?
- Marian Callanan's National Provider Identifier (NPI) is 1265484984, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Marian Callanan's specialty?
- Marian Callanan is listed in the NPPES registry with a primary specialty of Clinical Nurse Specialist (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Marian Callanan located?
- Marian Callanan's practice location on file with NPPES is 300 Pasteur Dr, Stanford, CA 94305-2200.
- What is Marian Callanan's phone number?
- The practice phone number listed in the NPPES registry for Marian Callanan is (650) 498-5710.
- Does Marian Callanan accept Medicare?
- Marian Callanan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Marian Callanan's NPI active?
- Yes — Marian Callanan's NPI (1265484984) is active in the NPPES registry as of the last update on 2023-07-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.