MARIMAR CONTRERAS NIEVES MD
NPI 1245767144
Internal Medicine - Nephrology in Palo Alto, CA
About Marimar Contreras Nieves Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARIMAR CONTRERAS NIEVES MD (NPI 1245767144) is an individual nephrology provider in Palo Alto, California, licensed in Georgia (110906) and active in the NPI registry since May 2017. She is enrolled in Medicare PECOS, maintains a secondary practice location in Palo Alto, and is a graduate of Other (2019).
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Marimar Contreras Nieves Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
3Medicare enrollment records show Marimar Contreras Nieves reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Palo Alto, CA 94304
- Reassigned Medicare billing, California enrollment
- 3,617 clinicians in this Medicare group
Stanford, CA 94305
- Reassigned Medicare billing, California enrollment
- 4,258 clinicians in this Medicare group
Atlanta, GA 30322
- Reassigned Medicare billing, Georgia enrollment
- 4,840 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 94301 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.
PALO ALTO, CA 94301
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 Marimar Contreras Nieves's NPI number?
The NPI number for Marimar Contreras Nieves is 1245767144. It was assigned to this individual provider in the NPPES registry on May 23, 2017.
Where is Marimar Contreras Nieves located?
Marimar Contreras Nieves practices at 795 El Camino Real, Palo Alto, CA 94301. The listed phone number is (650) 853-2917.
What is Marimar Contreras Nieves's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Nephrology, with taxonomy code 207RN0300X.
Is Marimar Contreras Nieves enrolled in Medicare?
Yes. Marimar Contreras Nieves is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Marimar Contreras Nieves's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Marimar Contreras Nieves reassigns Medicare benefits to 3 organizations: Lpch Medical Group Div Of Lucile (Palo Alto, CA), Stanford Health Care (Stanford, CA) and The Emory Clinic Inc (Atlanta, GA). 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 Marimar Contreras Nieves's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Marimar Contreras Nieves accept?
Health plans from Ambetter Health, Ambetter from Absolute Total Care, Ambetter of Alabama, Ambetter of North Carolina and Ambetter of Tennessee and 1 other insurer list Marimar Contreras Nieves as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
When was this NPI record last updated?
The NPPES record for Marimar Contreras Nieves was last updated on April 15, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 months 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.
# Marimar Contreras Nieves, MD · NPI 1245767144
Nephrology physician in Palo Alto, California. Individual provider, active in the CMS NPPES registry since May 23, 2017.
## Identity
- **NPI:** 1245767144 (Entity type: Individual)
- **Enumerated:** May 23, 2017
- **Primary specialty:** Internal Medicine - Nephrology · taxonomy 207RN0300X
- **State license:** 110906 (Georgia)
- **Sole proprietor:** No
## Practice location
- **Address:** 795 EL CAMINO REAL, Palo Alto, CA 94301-2302
- **Phone:** (650) 853-2917
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **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): Lpch Medical Group Div Of Lucile (NPI 1417907940, Palo Alto, CA); Stanford Health Care (NPI 1437292927, Stanford, CA); The Emory Clinic Inc (NPI 1396798229, Atlanta, GA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2019
## Record status
- **NPPES last updated:** April 15, 2026
---
Source: [NPI Profile](https://npiprofile.com/npi/1245767144) · Data from the CMS NPPES public registry.