COLIN MACKAY MD
NPI 1912683087
Internal Medicine in Evansville, IN
About Colin Mackay Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
COLIN MACKAY MD (NPI 1912683087) is an individual internal medicine provider in Evansville, Indiana, licensed in Indiana (11023241A) and active in the NPI registry since June 2023. He is enrolled in Medicare PECOS, is affiliated with Ascension St Vincent Evansville, and is a graduate of Other (2023).
NPPES Registry Identity
Specialties & Licenses 2
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Colin Mackay Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
2Medicare enrollment records show Colin Mackay reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Evansville, IN 47750
- Reassigned Medicare billing, Indiana enrollment
- Medicare enrollment name: St Marys Health Inc
- 75 clinicians in this Medicare group
Evansville, IN 47750
- Reassigned Medicare billing, Indiana enrollment
- Medicare enrollment name: St Marys Medical Group LLC
- 288 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
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Ascension St Vincent Evansville
Acute Care Hospitals · Evansville, INPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 47714 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
EVANSVILLE, IN 47714
EVANSVILLE, IN 47714
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 Colin Mackay's NPI number?
The NPI number for Colin Mackay is 1912683087. It was assigned to this individual provider in the NPPES registry on June 23, 2023.
Where is Colin Mackay located?
Colin Mackay practices at 3700 Washington Ave, Evansville, IN 47714. The listed phone number is (812) 485-4000.
What is Colin Mackay's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Colin Mackay enrolled in Medicare?
Yes. Colin Mackay is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Colin Mackay's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Colin Mackay reassigns Medicare benefits to 2 organizations: St. Mary's Health, Inc (Evansville, IN) and St Mary's Medical Group, LLC (Evansville, IN). Each 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 Colin Mackay's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Colin Mackay accept?
Health plans from Ambetter Health, Ambetter from Buckeye Health Plan and Ambetter from Meridian list Colin Mackay 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 Colin Mackay affiliated with any hospitals?
According to CMS data, Colin Mackay is affiliated with Ascension St Vincent Evansville.
When was this NPI record last updated?
The NPPES record for Colin Mackay was last updated on June 26, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 16 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.
# Colin Mackay, MD · NPI 1912683087
Internal Medicine physician in Evansville, Indiana. Individual provider, active in the CMS NPPES registry since June 23, 2023.
## Identity
- **NPI:** 1912683087 (Entity type: Individual)
- **Enumerated:** June 23, 2023
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** 11023241A (Indiana)
- **Sole proprietor:** No
## Practice location
- **Address:** 3700 WASHINGTON AVE, Evansville, IN 47714-0541
- **Phone:** (812) 485-4000
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): St. Mary's Health, Inc (NPI 1497706287, Evansville, IN); St Mary's Medical Group, LLC (NPI 1164852539, Evansville, IN) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2023
## Record status
- **NPPES last updated:** June 26, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1912683087) · Data from the CMS NPPES public registry.