DR. MARIA ISABEL CASTELLANOS M.D.
NPI 1881013795
Pediatrics in San Francisco, CA
About Dr. Maria Isabel Castellanos M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. MARIA ISABEL CASTELLANOS M.D. (NPI 1881013795) is an individual pediatrics provider in San Francisco, California, licensed in California (A138549) and active in the NPI registry since April 2014. She is enrolled in Medicare PECOS and maintains a secondary practice location in Oakland.
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Dr. Maria Isabel Castellanos M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
3Medicare enrollment records show Maria Castellanos reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
San Francisco, CA 94143
- Reassigned Medicare billing, California enrollment
- 1,159 clinicians in this Medicare group
San Francisco, CA 94143
- Reassigned Medicare billing, California enrollment
- 5,645 clinicians in this Medicare group
San Francisco, CA 94122
- Reassigned Medicare billing, California enrollment
- 5,544 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 94143 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
SAN FRANCISCO, CA 94143
SAN FRANCISCO, CA 94143
SAN FRANCISCO, CA 94143
SAN FRANCISCO, CA 94143
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Maria Castellanos's NPI number?
The NPI number for Maria Castellanos is 1881013795. It was assigned to this individual provider in the NPPES registry on April 8, 2014.
Where is Maria Castellanos located?
Maria Castellanos practices at 550 16th St, San Francisco, CA 94143. The listed phone number is (415) 476-3831.
What is Maria Castellanos's specialty?
The primary specialty registered for this NPI is Pediatrics with taxonomy code 208000000X.
Is Maria Castellanos enrolled in Medicare?
Yes. Maria Castellanos is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Maria Castellanos's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Maria Castellanos reassigns Medicare benefits to 3 organizations: Ucsf Pediatrics Associates (San Francisco, CA), University Of California San Francisco (San Francisco, CA) and Ucsf Medical Group Business Services (San Francisco, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Maria Castellanos's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Maria Castellanos was last updated on August 14, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Dr. Maria Isabel Castellanos, M.D. · NPI 1881013795
Pediatrics physician in San Francisco, California. Individual provider, active in the CMS NPPES registry since April 8, 2014.
## Identity
- **NPI:** 1881013795 (Entity type: Individual)
- **Enumerated:** April 8, 2014
- **Primary specialty:** Pediatrics · taxonomy 208000000X
- **State license:** A138549 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 550 16TH ST, San Francisco, CA 94143-2549
- **Phone:** (415) 476-3831
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 3 organizations under Medicare reassignment (form CMS-855R): Ucsf Pediatrics Associates (NPI 1376614016, San Francisco, CA); University Of California San Francisco (NPI 1346329380, San Francisco, CA); Ucsf Medical Group Business Services (NPI 1477624104, San Francisco, CA) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** August 14, 2024
---
Source: [NPI Profile](https://npiprofile.com/npi/1881013795) · Data from the CMS NPPES public registry.