DR. WILLIAM JOSEPH FREM DO
NPI 1831820646
Internal Medicine in Los Angeles, CA
About Dr. William Joseph Frem Do NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. WILLIAM JOSEPH FREM DO (NPI 1831820646) is an individual internal medicine provider in Los Angeles, California, licensed in California (20A22067) and active in the NPI registry since June 2022. He is enrolled in Medicare PECOS and is a graduate of Other (2022).
NPPES Registry Identity
Specialties & Licenses
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
Dr. William Joseph Frem Do 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
2Medicare enrollment records show William Frem reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Los Angeles, CA 90033
- Reassigned Medicare billing, California enrollment
- 962 clinicians in this Medicare group
Los Angeles, CA 90033
- Reassigned Medicare billing, California enrollment
- 131 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 90033 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.
LOS ANGELES, CA 90033
LOS ANGELES, CA 90033
LOS ANGELES, CA 90033
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 William Frem's NPI number?
The NPI number for William Frem is 1831820646. It was assigned to this individual provider in the NPPES registry on June 22, 2022.
Where is William Frem located?
William Frem practices at 1720 E Cesar E Chavez Ave, Los Angeles, CA 90033. The listed phone number is (323) 268-5000.
What is William Frem's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is William Frem enrolled in Medicare?
Yes. William Frem 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 William Frem's services?
According to the CMS Revalidation Reassignment List (October 2026 release), William Frem reassigns Medicare benefits to 2 organizations: Galen Inpatient Physicians PC (Los Angeles, CA) and White Memorial Medical Center (Los Angeles, 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 William Frem'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 William Frem was last updated on September 3, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 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.
# Dr. William Joseph Frem, DO · NPI 1831820646
Internal Medicine physician in Los Angeles, California. Individual provider, active in the CMS NPPES registry since June 22, 2022.
## Identity
- **NPI:** 1831820646 (Entity type: Individual)
- **Enumerated:** June 22, 2022
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** 20A22067 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 1720 E CESAR E CHAVEZ AVE, Los Angeles, CA 90033-2414
- **Phone:** (323) 268-5000
## 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:** 2 organizations under Medicare reassignment (form CMS-855R): Galen Inpatient Physicians PC (NPI 1205787686, Los Angeles, CA); White Memorial Medical Center (NPI 1215927470, Los Angeles, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2022
## Record status
- **NPPES last updated:** September 3, 2025
---
Source: [NPI Profile](https://npiprofile.com/npi/1831820646) · Data from the CMS NPPES public registry.