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COLORADO GASTROENTEROLOGY PROF LLC
NPI 1396790101
Internal Medicine - Gastroenterology in Denver, CO

Active since May 23, 2006
1960 N OGDEN ST STE 220, DENVER, CO 80218(303) 861-0808(303) 861-2193 Get Directions Write a Review

NPPES record last updated: April 21, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Colorado Gastroenterology Prof Llc NPPES

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

COLORADO GASTROENTEROLOGY PROF LLC (NPI 1396790101) is a healthcare organization registered as a gastroenterology in Denver, Colorado and active in the NPI registry since May 2006. The organization lists Kevin S Sieja, Managing Physician, as its authorized official.

NPPES Registry Identity

NPI1396790101
Entity TypeOrganization
Primary Taxonomy207RG0100X
Legal Business NameCOLORADO GASTROENTEROLOGY PROF LLC
Location Address1960 N OGDEN ST STE 220Denver, CO 80218-3668
Mailing Address1960 N Ogden St Ste 220Denver, CO 80218-3668 · (303) 861-0808 · Fax (303) 861-2193
Phone(303) 861-0808
Fax(303) 861-2193
Organization SubpartNo
Authorized OfficialKevin S SiejaManaging Physician · (303) 861-0808
Enumeration DateMay 23, 2006
Last NPPES UpdateApril 21, 2025
NPPES CertifiedApril 21, 2025
✔ NPI 1396790101 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians
Taxonomy Code207RG0100X
Definition
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.
1960 N OGDEN ST STE 220, Denver, CO 80218
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Other Identifiers 2

Medicaid9000152752CO
OtherDB9573CO · Railroad Medicare

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)

Colorado Gastroenterology Prof Llc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

7

Medicare enrollment records show 7 clinicians reassign Medicare billing to Colorado Gastroenterology Prof LLC, which bills Medicare for the services they deliver. Of these, 3 practice at this address and 5 within 10 miles. They are listed nearest first.

Clinicians, nearest first (7)

Thomas Trouillot, M.D.
Gastroenterology
NPI 1902850811
1960 OGDEN ST SUITE 220
Denver, CO 80218
(303) 861-0808
✔ PECOS✔ Accepts MedicareSame address
Jeffrey Frank, M.D.
Gastroenterology
NPI 1619922424
1960 OGDEN ST #220
Denver, CO 80218
(303) 861-0808
✔ PECOSSame address
Kevin Rufner, MD, MPH
Gastroenterology
NPI 1427195718
1960 N OGDEN ST STE 220
Denver, CO 80218
(303) 861-0808
✔ PECOS✔ Accepts MedicareSame address
Jennifer Brenner, M.D.
Gastroenterology
NPI 1760611305
4500 E 9TH AVE STE 720S
Denver, CO 80220
(303) 355-3525
✔ PECOS✔ Accepts Medicare2.4 mi
Kevin Sieja, M.D.
Gastroenterology
NPI 1952356677
4500 E 9TH AVE STE 720S
Denver, CO 80220
(303) 355-3525
✔ PECOS✔ Accepts Medicare2.4 mi
Michael Gilger, M.D.
Pathology
NPI 1467782003
7346 S ALTON WAY UNIT 10E
Centennial, CO 80112
(303) 770-4848
✔ PECOS✔ Accepts Medicare12 mi
Stephen Nash, MD
Pathology
NPI 1053414045
7346 S ALTON WAY SUITE 10-E
Centennial, CO 80112
(303) 770-4848
✔ PECOS12 mi

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 Colorado Gastroenterology Prof LLC's NPI number?

The NPI number for Colorado Gastroenterology Prof LLC is 1396790101. It was assigned to this organization in the NPPES registry on May 23, 2006.

Where is Colorado Gastroenterology Prof LLC located?

Colorado Gastroenterology Prof LLC is located at 1960 N Ogden St Ste 220, Denver, CO 80218. The listed phone number is (303) 861-0808.

What is Colorado Gastroenterology Prof LLC's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Colorado Gastroenterology Prof LLC enrolled in Medicare?

Yes. Colorado Gastroenterology Prof LLC is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Colorado Gastroenterology Prof LLC?

According to the CMS Revalidation Reassignment List (October 2026 release), 7 clinicians in 2 Medicare specialties reassign their Medicare billing to Colorado Gastroenterology Prof LLC. 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. The largest specialties are Gastroenterology (5) and Pathology (2). Of these, 3 practice at this address and 5 within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Colorado Gastroenterology Prof LLC was last updated on April 21, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 months 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.