Alfonso Tan, M.D.
NPI 1588689566 · Internal Medicine Physician · Sayville, NY
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Alfonso Tan, M.D. is a Internal Medicine Physician provider in Sayville, NY (NPI 1588689566).
Provider details
- NPI number
- 1588689566
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- 115465 (NY)
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
- 2006-07-12
- Last updated
- 2007-07-08
Frequently asked questions
- What is Alfonso Tan's NPI number?
- Alfonso Tan's National Provider Identifier (NPI) is 1588689566, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Alfonso Tan's specialty?
- Alfonso Tan is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Alfonso Tan located?
- Alfonso Tan's practice location on file with NPPES is 297 W Main St, Sayville, NY 11782-2523.
- What is Alfonso Tan's phone number?
- The practice phone number listed in the NPPES registry for Alfonso Tan is (631) 589-2323.
- Does Alfonso Tan accept Medicare?
- Alfonso Tan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Alfonso Tan's NPI active?
- Yes — Alfonso Tan's NPI (1588689566) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.