MARCUS WESLEY LUM MD
NPI 1003839242
Family Medicine in La Mirada, CA
About Marcus Wesley Lum Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARCUS WESLEY LUM MD (NPI 1003839242) is an individual family medicine provider in La Mirada, California, licensed in California (G073347) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS and is a graduate of Other (1990).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 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
Marcus Wesley Lum 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 Reassignment
Medicare enrollment records show Marcus Lum reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
La Mirada, CA 90638
- Reassigned Medicare billing, California enrollment
- 6 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.
Areas of Expertise CMS Part B claims 7
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 90638 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 5
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
LA MIRADA, CA 90638
LA MIRADA, CA 90638
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 Marcus Lum's NPI number?
The NPI number for Marcus Lum is 1003839242. It was assigned to this individual provider in the NPPES registry on July 26, 2006.
Where is Marcus Lum located?
Marcus Lum practices at 15034 Imperial Hwy, La Mirada, CA 90638. The listed phone number is (562) 902-3000.
What is Marcus Lum's specialty?
The primary specialty registered for this NPI is Family Medicine with taxonomy code 207Q00000X.
Is Marcus Lum enrolled in Medicare?
Yes. Marcus Lum 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 organization bills Medicare for Marcus Lum's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Marcus Lum reassigns Medicare benefits to Imperial Primary Care Medical Group (La Mirada, CA). The 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 Marcus Lum'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 Marcus Lum was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 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.
# Marcus Wesley Lum, MD · NPI 1003839242
Family Medicine physician in La Mirada, California. Individual provider, active in the CMS NPPES registry since July 26, 2006.
## Identity
- **NPI:** 1003839242 (Entity type: Individual)
- **Enumerated:** July 26, 2006
- **Primary specialty:** Family Medicine · taxonomy 207Q00000X
- **State license:** G073347 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 15034 IMPERIAL HWY, La Mirada, CA 90638-1301
- **Phone:** (562) 902-3000 · **Fax:** (562) 902-9563
## 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:** Imperial Primary Care Medical Group (NPI 1598893455, La Mirada, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 1990
## Record status
- **NPPES last updated:** July 8, 2007
- **Other identifiers:** Medicare UPIN F38991 (CA)
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Source: [NPI Profile](https://npiprofile.com/npi/1003839242) · Data from the CMS NPPES public registry.