Mark Tieman, MD, PC
NPI 1821375940 · Primary Care Clinic/Center · Commack, NY
Enrolled with Medicare as Part B Supplier - Clinic/Group Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Tieman, MD, PC is a Primary Care Clinic/Center organization in Commack, NY (NPI 1821375940).
Provider details
- NPI number
- 1821375940
- Entity type
- Organization
- Primary specialty
- Primary Care Clinic/CenterAmbulatory Health Care Facilities
- Organization subpart
- No
- Authorized official
- Mark Tieman, President(631) 424-9844
- License
- 179172 (NY)
Specialties & taxonomies
Ambulatory Health Care Facilities
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
14 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
- 2011-11-03
- Last updated
- 2011-11-03
Frequently asked questions
- What is Mark Tieman, MD, PC's NPI number?
- Mark Tieman, MD, PC's National Provider Identifier (NPI) is 1821375940, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What type of organization is Mark Tieman, MD, PC?
- Mark Tieman, MD, PC is classified in the NPPES registry as Primary Care Clinic/Center (Ambulatory Health Care Facilities).
- Where is Mark Tieman, MD, PC located?
- Mark Tieman, MD, PC's practice location on file with NPPES is 356 Veterans Memorial Hwy, Commack, NY 11725-4343.
- What is Mark Tieman, MD, PC's phone number?
- The practice phone number listed in the NPPES registry for Mark Tieman, MD, PC is (631) 858-0400.
- Does Mark Tieman, MD, PC accept Medicare?
- Mark Tieman, MD, PC is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Who is the authorized official for Mark Tieman, MD, PC?
- The authorized official listed on Mark Tieman, MD, PC's NPPES record is Mark Tieman, President. The authorized official registers and maintains the organization's NPI and is not necessarily its owner.
- Is Mark Tieman, MD, PC's NPI active?
- Yes — Mark Tieman, MD, PC's NPI (1821375940) is active in the NPPES registry as of the last update on 2011-11-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.