BAY INFECTIOUS DISEASE MEDICAL GROUP
NPI 1215137633
Internal Medicine - Infectious Disease in Orinda, CA

Q: What is Bay Infectious Disease's NPI number?

The NPI number for Bay Infectious Disease is 1215137633. It was assigned to this organization in the NPPES registry on July 24, 2007. The provider is also known as Bay Infectious Disease Medical Group.

Q: What is Bay Infectious Disease's specialty?

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

Active since July 24, 2007

1 COUNTRY CLUB PLZ, ORINDA, CA 94563(925) 254-3805(925) 254-9783 Get Directions Write a Review

NPPES record last updated: January 7, 2013. Verified against the NPPES registry weekly; last sync: October 25, 2026.

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About Bay Infectious Disease Medical Group NPPES

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

BAY INFECTIOUS DISEASE MEDICAL GROUP (NPI 1215137633) is a healthcare organization registered as an infectious disease in Orinda, California and active in the NPI registry since July 2007. The organization lists Yenjean Syn Hwang, Partner, as its authorized official.

NPPES Registry Identity

NPI1215137633

Entity TypeOrganization

Primary Taxonomy207RI0200X

Legal Business NameBAY INFECTIOUS DISEASE

Location Address1 COUNTRY CLUB PLZOrinda, CA 94563-2308

Mailing Address1 Country Club PlzOrinda, CA 94563-2308 · (925) 254-3805 · Fax (925) 254-9783

Phone(925) 254-3805

Fax(925) 254-9783

Organization SubpartNo

Authorized OfficialYenjean Syn HwangPartner · (925) 254-3805

Enumeration DateJuly 24, 2007

Last NPPES UpdateJanuary 7, 2013

✔ NPI 1215137633 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Infectious DiseaseAllopathic & Osteopathic Physicians

Taxonomy Code207RI0200X

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.

1 COUNTRY CLUB PLZ, Orinda, CA 94563

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Other Names 1

Other NameBay Infectious Disease Medical Group

Other Identifiers 1

Medicare UPINZZZ01156ZCA

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Bay Infectious Disease Medical Group is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 2 clinicians reassign Medicare billing to Bay Infectious Disease Medical Group, which bills Medicare for the services they deliver. Of these, 2 practice within 10 miles. They are listed nearest first.

Clinicians, nearest first (2)

Yenjean Hwang, M.D.

Infectious Disease

NPI 1194744557

3100 SUMMIT STREET 2ND FLOOR
Oakland, CA 94609

(510) 869-8400

✔ PECOS✔ Accepts Medicare6.0 mi

David Perlada, M.D.

Infectious Disease

NPI 1245259845

1 COUNTRY CLUB PLZ
Orinda, CA 94563

(925) 254-3805

✔ PECOS✔ Accepts Medicare6.8 mi

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

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 Bay Infectious Disease's NPI number?

The NPI number for Bay Infectious Disease is 1215137633. It was assigned to this organization in the NPPES registry on July 24, 2007. The provider is also known as Bay Infectious Disease Medical Group.

Where is Bay Infectious Disease located?

Bay Infectious Disease is located at 1 Country Club Plz, Orinda, CA 94563. The listed phone number is (925) 254-3805.

What is Bay Infectious Disease's specialty?

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

Is Bay Infectious Disease enrolled in Medicare?

Yes. Bay Infectious Disease is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Bay Infectious Disease?

According to the CMS Revalidation Reassignment List (October 2026 release), 2 clinicians, all in Infectious Disease, reassign their Medicare billing to Bay Infectious Disease. A 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 the clinician's services. Of these, 2 practice within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Bay Infectious Disease was last updated on January 7, 2013. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 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.