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CATHERINE S MAO M.D.
NPI 1073567236
Pediatrics - Pediatric Endocrinology in Torrance, CA

Active since May 20, 2006PECOS Enrolled
21840 NORMANDIE AVE, STE. 1100, TORRANCE, CA 90502(310) 222-5133(310) 781-9352 Get Directions Write a Review

NPPES record last updated: July 23, 2019. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Jul 23, 2019, May 21, 2019 (2 updates tracked since 2019).

About Catherine S Mao M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

CATHERINE S MAO M.D. (NPI 1073567236) is an individual pediatric endocrinology provider in Torrance, California, licensed in California (A51970) and active in the NPI registry since May 2006. She is enrolled in Medicare PECOS and maintains a secondary practice location in Torrance.

NPPES Registry Identity

NPI1073567236
Entity TypeIndividualFemale
Primary Taxonomy2080P0205X
Provider Legal NameCATHERINE S MAOCredential: M.D.
Location Address21840 NORMANDIE AVE, STE. 1100Torrance, CA 90502-2047
Mailing Address21840 Normandie Ave Ste 700Torrance, CA 90502-2047 · (310) 222-5189 · Fax (310) 328-1415
Phone(310) 222-5133
Fax(310) 781-9352
Sole ProprietorNo
Enumeration DateMay 20, 2006
Last NPPES UpdateJuly 23, 20192 updates tracked since enumeration
✔ NPI 1073567236 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPediatrics · Pediatric EndocrinologyAllopathic & Osteopathic Physicians
Taxonomy Code2080P0205X
License✔ Licensed in CA · A51970
Definition
A pediatrician who provides expert care to infants, children and adolescents who have diseases that result from an abnormality in the endocrine glands (glands which secrete hormones). These diseases include diabetes mellitus, growth failure, unusual size for age, early or late pubertal development, birth defects, the genital region and disorders of the thyroid, the adrenal and pituitary glands.
21840 NORMANDIE AVE, Torrance, CA 90502
Open in Google Maps ↗

Secondary Practice Location 1

Location 11000 W Carson StTorrance, CA 90502-2004 · Phone (310) 222-5189

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Catherine S Mao M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

2

Medicare enrollment records show Catherine Mao reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Prohealth Partners A Medical Group
Same address
Family Medicine
21840 NORMANDIE AVE
Torrance, CA 90502
  • Reassigned Medicare billing, California enrollment
  • 279 clinicians in this Medicare group
NPI 1609226877 (310) 222-5189
County Of Los Angeles
0.4 mi
General Acute Care Hospital
1000 W CARSON ST # 2
Torrance, CA 90502
  • Reassigned Medicare billing, California enrollment
  • 1,939 clinicians in this Medicare group
NPI 1851363188 (310) 222-2171

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 90502 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$142.39 typical visit price
range $62.96 – $187.60
Typical copayment $35.59 (range $15.74 – $46.90)
Most-billed visit code 99204
Established Patient
$109.96 typical visit price
range $20.84 – $153.61
Typical copayment $27.49 (range $5.21 – $38.40)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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.

KATAYOUN K MOSTAFAIE M.D.
General Practice
21840 NORMANDIE AVE, STE. 700
TORRANCE, CA 90502
Los Angeles County (310) 222-5101
ANDREW G GIANOUKAKIS M.D.
Internal Medicine (Endocrinology, Diabetes & Metabolism)
21840 NORMANDIE AVE, STE. 700
TORRANCE, CA 90502
Los Angeles County (310) 222-5183
KATHY E SIETSEMA M.D.
Internal Medicine (Pulmonary Disease)
21840 NORMANDIE AVE
TORRANCE, CA 90502
Los Angeles County (310) 222-5101
MARK T. MUNEKATA M.D.
General Practice
21840 NORMANDIE AVE, STE. 700
TORRANCE, CA 90502
Los Angeles County (310) 222-5101
JOEL D. KOPPLE M.D.
Internal Medicine (Nephrology)
21840 NORMANDIE AVE, STE. 700
TORRANCE, CA 90502
Los Angeles County (310) 222-5101
NEDILJKA BULJUBASIC M.D.
Internal Medicine (Cardiovascular Disease)
21840 NORMANDIE AVE, STE. 700
TORRANCE, CA 90502
Los Angeles County (310) 222-5101
RONALD SWERDLOFF M.D.
Internal Medicine (Endocrinology, Diabetes & Metabolism)
21840 NORMANDIE AVE, STE. 700
TORRANCE, CA 90502
Los Angeles County (310) 222-5101
JOHN W TSUANG M.D.
Psychiatry & Neurology (Psychiatry)
21840 NORMANDIE AVE, STE. 200
TORRANCE, CA 90502
Los Angeles County (310) 222-3101

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 Catherine Mao's NPI number?

The NPI number for Catherine Mao is 1073567236. It was assigned to this individual provider in the NPPES registry on May 20, 2006.

Where is Catherine Mao located?

Catherine Mao practices at 21840 Normandie Ave Ste. 1100, Torrance, CA 90502. The listed phone number is (310) 222-5133.

What is Catherine Mao's specialty?

The primary specialty registered for this NPI is Pediatrics, specializing in Pediatric Endocrinology, with taxonomy code 2080P0205X.

Is Catherine Mao enrolled in Medicare?

Yes. Catherine Mao is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Catherine Mao's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Catherine Mao reassigns Medicare benefits to 2 organizations: Prohealth Partners A Medical Group (Torrance, CA) and County Of Los Angeles (Torrance, 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 Catherine Mao'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 Catherine Mao was last updated on July 23, 2019. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 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.