OrganizationActive
Mark R Northfield, M.D.
NPI 1609051572 · Specialist · Petaluma, CA
Mark R Northfield, M.D. is a Specialist organization in Petaluma, CA (NPI 1609051572).
Provider details
- NPI number
- 1609051572
- Entity type
- Organization
- Primary specialty
- SpecialistOther Service Providers
- Organization subpart
- No
- Authorized official
- Lee Brill, Receptionist(707) 778-1131
- License
- G77114 (CA)
Specialties & taxonomies
Other Service Providers
Profile Score
Detailed profile(88/100 index)
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
18 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
1496 Professional Dr
Suite 601
Petaluma, CA 94954-6698
Phone: (707) 778-1131
Fax: (707) 778-3818
Street-level locationGet directions
Mailing address
1496 Professional Dr
Petaluma, CA 94954-6698
Registry dates
- Enumerated
- 2008-01-09
- Last updated
- 2008-01-09
Frequently asked questions
- What is Mark R Northfield, M.D.'s NPI number?
- Mark R Northfield, M.D.'s National Provider Identifier (NPI) is 1609051572, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What type of organization is Mark R Northfield, M.D.?
- Mark R Northfield, M.D. is classified in the NPPES registry as Specialist (Other Service Providers).
- Where is Mark R Northfield, M.D. located?
- Mark R Northfield, M.D.'s practice location on file with NPPES is 1496 Professional Dr, Petaluma, CA 94954-6698.
- What is Mark R Northfield, M.D.'s phone number?
- The practice phone number listed in the NPPES registry for Mark R Northfield, M.D. is (707) 778-1131.
- Who is the authorized official for Mark R Northfield, M.D.?
- The authorized official listed on Mark R Northfield, M.D.'s NPPES record is Lee Brill, Receptionist. The authorized official registers and maintains the organization's NPI and is not necessarily its owner.
- Is Mark R Northfield, M.D.'s NPI active?
- Yes — Mark R Northfield, M.D.'s NPI (1609051572) is active in the NPPES registry as of the last update on 2008-01-09.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.