Mark Nielsen, M.D.
NPI 1922056894 · Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician · Sioux City, IA
Mark Nielsen, M.D. is a Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician provider in Sioux City, IA (NPI 1922056894).
Provider details
- NPI number
- 1922056894
- Entity type
- Individual
- Primary specialty
- Thoracic Surgery (Cardiothoracic Vascular Surgery) PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- 036115004 (IA)
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
20 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
- 2006-05-04
- Last updated
- 2009-12-07
Frequently asked questions
- What is Mark Nielsen's NPI number?
- Mark Nielsen's National Provider Identifier (NPI) is 1922056894, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Nielsen's specialty?
- Mark Nielsen is listed in the NPPES registry with a primary specialty of Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Nielsen located?
- Mark Nielsen's practice location on file with NPPES is 4630 Singing Hills Blvd, Sioux City, IA 51106-9702.
- What is Mark Nielsen's phone number?
- The practice phone number listed in the NPPES registry for Mark Nielsen is (712) 271-8346.
- Is Mark Nielsen's NPI active?
- Yes — Mark Nielsen's NPI (1922056894) is active in the NPPES registry as of the last update on 2009-12-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.