MICHAEL J DRINNAN MD
NPI 1609883024
Ophthalmology in San Mateo, CA
About Michael J Drinnan Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MICHAEL J DRINNAN MD (NPI 1609883024) is an individual ophthalmology provider in San Mateo, California, licensed in California (G50381) and active in the NPI registry since August 2006. He is enrolled in Medicare PECOS and is a graduate of Other (1982).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 2
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
Michael J Drinnan 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 Reassignments
2Medicare enrollment records show Michael Drinnan reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
San Mateo, CA 94401
- Reassigned Medicare billing, California enrollment
- 9 clinicians in this Medicare group
Palo Alto, CA 94306
- Reassigned Medicare billing, California enrollment
- 2,460 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 13
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 94401 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
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.
SAN MATEO, CA 94401
SAN MATEO, CA 94401
SAN MATEO, CA 94401
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 Michael Drinnan's NPI number?
The NPI number for Michael Drinnan is 1609883024. It was assigned to this individual provider in the NPPES registry on August 1, 2006.
Where is Michael Drinnan located?
Michael Drinnan practices at 101 S San Mateo Dr Suite 310, San Mateo, CA 94401. The listed phone number is (650) 342-7474.
What is Michael Drinnan's specialty?
The primary specialty registered for this NPI is Ophthalmology with taxonomy code 207W00000X.
Is Michael Drinnan enrolled in Medicare?
Yes. Michael Drinnan 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 Michael Drinnan's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Michael Drinnan reassigns Medicare benefits to 2 organizations: Peninsula Eye Physicians Medical Group,inc. (San Mateo, CA) and County Of Santa Clara (Palo Alto, 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 Michael Drinnan'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 Michael Drinnan was last updated on October 23, 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.
# Michael J Drinnan, MD · NPI 1609883024
Ophthalmology physician in San Mateo, California. Individual provider, active in the CMS NPPES registry since August 1, 2006.
## Identity
- **NPI:** 1609883024 (Entity type: Individual)
- **Enumerated:** August 1, 2006
- **Primary specialty:** Ophthalmology · taxonomy 207W00000X
- **State license:** G50381 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 101 S SAN MATEO DR, SUITE 310, San Mateo, CA 94401-3819
- **Phone:** (650) 342-7474 · **Fax:** (650) 342-9260
## 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): Peninsula Eye Physicians Medical Group,inc. (NPI 1346255064, San Mateo, CA); County Of Santa Clara (NPI 1144330614, Palo Alto, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 1982
## Record status
- **NPPES last updated:** October 23, 2007
- **Other identifiers:** Medicare UPIN A51661 (CA); Medicare PIN 00G503810 (CA)
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Source: [NPI Profile](https://npiprofile.com/npi/1609883024) · Data from the CMS NPPES public registry.