William Janssen, MD
NPI 1811905367 · Pulmonary Disease Physician · Denver, CO
Enrolled with Medicare as Practitioner - Pulmonary Disease · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Janssen, MD is a Pulmonary Disease Physician provider in Denver, CO (NPI 1811905367).
Provider details
- NPI number
- 1811905367
- Entity type
- Individual
- Primary specialty
- Pulmonary Disease PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 41254 (CO)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
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
2 documented practice locations
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
Additional practice locations (1)
- 12605 E 16th AveAurora, CO 80045-2545Phone: (720) 848-0000
Registry dates
- Enumerated
- 2006-08-03
- Last updated
- 2021-02-23
- Certified
- 2021-02-23
Frequently asked questions
- What is William Janssen's NPI number?
- William Janssen's National Provider Identifier (NPI) is 1811905367, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Janssen's specialty?
- William Janssen is listed in the NPPES registry with a primary specialty of Pulmonary Disease Physician (Allopathic & Osteopathic Physicians).
- Where is William Janssen located?
- William Janssen's practice location on file with NPPES is 1400 Jackson St, Denver, CO 80206-2761.
- What is William Janssen's phone number?
- The practice phone number listed in the NPPES registry for William Janssen is (303) 388-4461.
- Does William Janssen accept Medicare?
- William Janssen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Janssen's NPI active?
- Yes — William Janssen's NPI (1811905367) is active in the NPPES registry as of the last update on 2021-02-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.