Frederick E. Siefert, MD, PC
NPI 1417093683 · Internal Medicine Physician · Old Greenwich, CT
Frederick E. Siefert, MD, PC is a Internal Medicine Physician organization in Old Greenwich, CT (NPI 1417093683).
Provider details
- NPI number
- 1417093683
- Entity type
- Organization
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Organization subpart
- No
- Authorized official
- Frederick Siefert, President(203) 637-5406
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 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
Mailing address
Registry dates
- Enumerated
- 2007-01-29
- Last updated
- 2007-09-10
Frequently asked questions
- What is Frederick E. Siefert, MD, PC's NPI number?
- Frederick E. Siefert, MD, PC's National Provider Identifier (NPI) is 1417093683, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What type of organization is Frederick E. Siefert, MD, PC?
- Frederick E. Siefert, MD, PC is classified in the NPPES registry as Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Frederick E. Siefert, MD, PC located?
- Frederick E. Siefert, MD, PC's practice location on file with NPPES is 8 W End Ave, Old Greenwich, CT 06870-1642.
- What is Frederick E. Siefert, MD, PC's phone number?
- The practice phone number listed in the NPPES registry for Frederick E. Siefert, MD, PC is (203) 637-5406.
- Who is the authorized official for Frederick E. Siefert, MD, PC?
- The authorized official listed on Frederick E. Siefert, MD, PC's NPPES record is Frederick Siefert, President. The authorized official registers and maintains the organization's NPI and is not necessarily its owner.
- Is Frederick E. Siefert, MD, PC's NPI active?
- Yes — Frederick E. Siefert, MD, PC's NPI (1417093683) is active in the NPPES registry as of the last update on 2007-09-10.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.