MARK IRWIN
NPI 1104453588
Internal Medicine - Infectious Disease in Knoxville, TN
About Mark Irwin NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARK IRWIN (NPI 1104453588) is an individual infectious disease provider in Knoxville, Tennessee, licensed in Tennessee (6170) and active in the NPI registry since March 2020. He is enrolled in Medicare PECOS, is affiliated with Roane Medical Center, and is a graduate of Other (2020).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 1
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Mark Irwin is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignment
Medicare enrollment records show Mark Irwin reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Knoxville, TN 37932
- Reassigned Medicare billing, Tennessee enrollment
- 504 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Hospital Affiliations CMS Care Compare 4
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Roane Medical Center
Acute Care Hospitals · Harriman, TNFort Loudoun Medical Center
Acute Care Hospitals · Lenoir City, TNFort Sanders Regional Medical Center
Acute Care Hospitals · Knoxville, TNParkwest Medical Center
Acute Care Hospitals · Knoxville, TNPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 37916 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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 Irwin's NPI number?
The NPI number for Mark Irwin is 1104453588. It was assigned to this individual provider in the NPPES registry on March 25, 2020.
Where is Mark Irwin located?
Mark Irwin practices at 501 19th St Ste 600, Knoxville, TN 37916. The listed phone number is (865) 525-4333.
What is Mark Irwin's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Infectious Disease, with taxonomy code 207RI0200X.
Is Mark Irwin enrolled in Medicare?
Yes. Mark Irwin is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organization bills Medicare for Mark Irwin's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mark Irwin reassigns Medicare benefits to Covenant Medical Group, Inc. (Knoxville, TN). The 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 Mark Irwin's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Mark Irwin accept?
Health plans from Ambetter Health, Ambetter from Arkansas Health & Wellness, Ambetter of Alabama, Ambetter of North Carolina and Ambetter of Tennessee and 3 other insurers list Mark Irwin as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Mark Irwin affiliated with any hospitals?
According to CMS data, Mark Irwin is affiliated with Roane Medical Center, Fort Loudoun Medical Center, Fort Sanders Regional Medical Center and Parkwest Medical Center.
When was this NPI record last updated?
The NPPES record for Mark Irwin was last updated on July 21, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 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.
# Mark Irwin · NPI 1104453588
Infectious Disease physician in Knoxville, Tennessee. Individual provider, active in the CMS NPPES registry since March 25, 2020.
## Identity
- **NPI:** 1104453588 (Entity type: Individual)
- **Enumerated:** March 25, 2020
- **Primary specialty:** Internal Medicine - Infectious Disease · taxonomy 207RI0200X
- **State license:** 6170 (Tennessee)
- **Sole proprietor:** No
## Practice location
- **Address:** 501 19TH ST STE 600, Knoxville, TN 37916-1852
- **Phone:** (865) 525-4333
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** Covenant Medical Group, Inc. (NPI 1457302010, Knoxville, TN), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2020
## Record status
- **NPPES last updated:** July 21, 2025
- **Other identifiers:** Medicaid Q102113 (TN)
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Source: [NPI Profile](https://npiprofile.com/npi/1104453588) · Data from the CMS NPPES public registry.