ALEXANDER NATHAN KLONOFF M.D.
NPI 1538629936
Internal Medicine in Los Angeles, CA
About Alexander Nathan Klonoff M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
ALEXANDER NATHAN KLONOFF M.D. (NPI 1538629936) is an individual internal medicine provider in Los Angeles, California, licensed in California (A177588) and active in the NPI registry since March 2019. He is enrolled in Medicare PECOS, maintains a secondary practice location in West Hollywood, and is a graduate of University Of Southern California Keck School Of Medicine (2019).
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 and accepts Medicare assignment
Alexander Nathan Klonoff M.d. 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 Alexander Klonoff 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 90027
- Reassigned Medicare billing, California enrollment
- 13,921 clinicians in this Medicare group
Los Angeles, CA 90048
- Reassigned Medicare billing, California enrollment
- 2,118 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 90089 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 90089
LOS ANGELES, CA 90089
LOS ANGELES, CA 90089
LOS ANGELES, CA 90089
LOS ANGELES, CA 90089
LOS ANGELES, CA 90089
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 Alexander Klonoff's NPI number?
The NPI number for Alexander Klonoff is 1538629936. It was assigned to this individual provider in the NPPES registry on March 21, 2019.
Where is Alexander Klonoff located?
Alexander Klonoff practices at 1200 N State St Clinic Tower, Suite A7d, Los Angeles, CA 90089. The listed phone number is (323) 409-7556.
What is Alexander Klonoff's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Alexander Klonoff enrolled in Medicare?
Yes. Alexander Klonoff 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 Alexander Klonoff's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Alexander Klonoff reassigns Medicare benefits to 2 organizations: Southern California Permanente Medical Group (Los Angeles, CA) and Cedars-Sinai Medical Care Foundation (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 Alexander Klonoff'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 Alexander Klonoff was last updated on April 9, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 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.
# Alexander Nathan Klonoff, M.D. · NPI 1538629936
Internal Medicine physician in Los Angeles, California. Individual provider, active in the CMS NPPES registry since March 21, 2019.
## Identity
- **NPI:** 1538629936 (Entity type: Individual)
- **Enumerated:** March 21, 2019
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** A177588 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 1200 N STATE ST, CLINIC TOWER, SUITE A7D, Los Angeles, CA 90089-1001
- **Phone:** (323) 409-7556
## 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): Southern California Permanente Medical Group (NPI 1134151657, Los Angeles, CA); Cedars-Sinai Medical Care Foundation (NPI 1316984388, Los Angeles, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Southern California Keck School Of Medicine, class of 2019
## Record status
- **NPPES last updated:** April 9, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1538629936) · Data from the CMS NPPES public registry.