1. Home
  2. Directory
  3. New York
  4. Smithtown
  5. Specialist
  6. NPI Profile

MARK TAN, M.D., P.C.
NPI 1386828861
Specialist in Smithtown, NY

Active since December 20, 2007
222 MIDDLE COUNTRY RD, SUITE # 312, SMITHTOWN, NY 11787(631) 821-5893(631) 724-8901 Get Directions Write a Review

NPPES record last updated: January 7, 2008. Verified against the NPPES registry weekly; last sync: November 01, 2026.

About Mark Tan, M.d., P.c. NPPES

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

MARK TAN, M.D., P.C. (NPI 1386828861) is a healthcare organization registered as a specialist in Smithtown, New York and active in the NPI registry since December 2007. The organization lists Mark Tan, Owner, as its authorized official.

NPPES Registry Identity

NPI1386828861
Entity TypeOrganization
Primary Taxonomy174400000X
Legal Business NameMARK TAN, M.D., P.C.
Location Address222 MIDDLE COUNTRY RD, SUITE # 312Smithtown, NY 11787
Mailing Address222 Middle Country Rd, Suite # 312Smithtown, NY 11787-2871 · (631) 821-5893 · Fax (631) 724-8901
Phone(631) 821-5893
Fax(631) 724-8901
Organization SubpartNo
Authorized OfficialMark TanOwner · (631) 724-8900
Enumeration DateDecember 20, 2007
Last NPPES UpdateJanuary 7, 2008
✔ NPI 1386828861 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySpecialistOther Service Providers
Taxonomy Code174400000X
License✔ Licensed in NY · 165674
Definition
An individual educated and trained in an applied knowledge discipline used in the performance of work at a level requiring knowledge and skills beyond or apart from that provided by a general education or liberal arts degree.
222 MIDDLE COUNTRY RD, Smithtown, NY 11787
Open in Google Maps ↗

Other Identifiers 3

Medicaid00986705NY
Medicare UPINC58894NY
Medicare PINWES521NY

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)

Mark Tan, M.d., P.c. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 1 clinician reassigns Medicare billing to Mark Tan, M.D., P.C., which bills Medicare for the services this clinician delivers.

Clinician (1)

Mark Tan, M.D.
Rheumatology
NPI 1083770580
222 MIDDLE COUNTRY ROAD SUITE 312
Smithtown, NY 11787
(631) 724-8900
✔ PECOS✔ Accepts MedicareSame address

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 Mark Tan, M.D., P.C.'s NPI number?

The NPI number for Mark Tan, M.D., P.C. is 1386828861. It was assigned to this organization in the NPPES registry on December 20, 2007.

Where is Mark Tan, M.D., P.C. located?

Mark Tan, M.D., P.C. is located at 222 Middle Country Rd Suite # 312, Smithtown, NY 11787. The listed phone number is (631) 821-5893.

What is Mark Tan, M.D., P.C.'s specialty?

The primary specialty registered for this NPI is Specialist with taxonomy code 174400000X.

Is Mark Tan, M.D., P.C. enrolled in Medicare?

Yes. Mark Tan, M.D., P.C. is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Mark Tan, M.D., P.C.?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Rheumatology) reassigns their Medicare billing to Mark Tan, M.D., P.C.. 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. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Mark Tan, M.D., P.C. was last updated on January 7, 2008. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 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.