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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

DR. WILLIAM RITCHIE MACKENZIE M.D.
NPI 1073561601
Internal Medicine - Infectious Disease in Mather, CA

Active since May 05, 2006
10535 HOSPITAL WAY, MATHER, CA 95655(916) 843-7107 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 16, 2026.

About Dr. William Ritchie Mackenzie M.d. NPPES

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

DR. WILLIAM RITCHIE MACKENZIE M.D. (NPI 1073561601) is an individual infectious disease provider in Mather, California, licensed in California (G59633) and active in the NPI registry since May 2006.

NPPES Registry Identity

NPI1073561601
Entity TypeIndividualMale
Primary Taxonomy207RI0200X
Provider Legal NameDR. WILLIAM RITCHIE MACKENZIECredential: M.D.
Location Address10535 HOSPITAL WAYMather, CA 95655-4200
Mailing Address380 World Way, Box N-19Los Angeles, CA 90045-5800 · (310) 215-2365 · Fax (310) 215-2285
Phone(916) 843-7107
Sole ProprietorNo
Enumeration DateMay 5, 2006
Last NPPES UpdateJuly 13, 2026
✔ NPI 1073561601 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Infectious DiseaseAllopathic & Osteopathic Physicians
Taxonomy Code207RI0200X
License✔ Licensed in CA · G59633
Definition
An internist who deals with infectious diseases of all types and in all organ systems. Conditions requiring selective use of antibiotics call for this special skill. This physician often diagnoses and treats AIDS patients and patients with fevers which have not been explained. Infectious disease specialists may also have expertise in preventive medicine and travel medicine.
10535 HOSPITAL WAY, Mather, CA 95655
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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.

ALAYNA HUYNH NGUYEN
Pharmacist
10535 HOSPITAL WAY
MATHER, CA 95655
Sacramento County (916) 843-7000
MS. JANE CHAN RPH
Pharmacist
10535 HOSPITAL WAY
MATHER, CA 95655
Sacramento County (916) 366-5321
DR. PATRICIA L. DALTON M.D.
Specialist
10535 HOSPITAL WAY, DEPT. OF VA SACRAMENTO MEDICAL CENTER
MATHER, CA 95655
Sacramento County (916) 843-7000
SHIN SHAN CHO
Dietitian, Registered
10535 HOSPITAL WAY
MATHER, CA 95655
Sacramento County (916) 843-9022
BRENDA JACKSON LMFT
Marriage & Family Therapist
10535 HOSPITAL WAY
MATHER, CA 95655
Sacramento County (916) 843-2918
JEFFREY JON METER MD
Orthopaedic Surgery (Orthopaedic Surgery of the Spine)
10535 HOSPITAL WAY
MATHER, CA 95655
Sacramento County (916) 843-7324
DR. DAVID SIEGEL M.D.
Internal Medicine
10535 HOSPITAL WAY
MATHER, CA 95655
Sacramento County (916) 843-7096
ERICKA RAMIREZ-SOLIS PH.D.
Psychologist (Clinical)
10535 HOSPITAL WAY
MATHER, CA 95655
Sacramento County (800) 382-8387

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 Mackenzie's NPI number?

The NPI number for William Mackenzie is 1073561601. It was assigned to this individual provider in the NPPES registry on May 5, 2006.

Where is William Mackenzie located?

William Mackenzie practices at 10535 Hospital Way, Mather, CA 95655. The listed phone number is (916) 843-7107.

What is William Mackenzie's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Infectious Disease, with taxonomy code 207RI0200X.

When was this NPI record last updated?

The NPPES record for William Mackenzie was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 39 days 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.