DR. LEE MICHAEL DEMERTZIS MD
NPI 1831298827
Internal Medicine - Critical Care Medicine in Saint Louis, MO
About Dr. Lee Michael Demertzis Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. LEE MICHAEL DEMERTZIS MD (NPI 1831298827) is an individual critical care medicine provider in Saint Louis, Missouri, licensed in Missouri (2006001553) and active in the NPI registry since September 2006. He is enrolled in Medicare PECOS, is affiliated with Mercy Hospital South, and is a graduate of Emory University School Of Medicine (2004).
NPPES Registry Identity
Specialties & Licenses 2
Other Identifiers 3
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
Dr. Lee Michael Demertzis Md 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 Reassignments
2Medicare enrollment records show Lee Demertzis reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Saint Louis, MO 63141
- Reassigned Medicare billing, Missouri enrollment
- 77 clinicians in this Medicare group
Oak Ridge, TN 37830
- Reassigned Medicare billing, Missouri enrollment
- 193 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.
Areas of Expertise CMS Part B claims 5
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Hospital Affiliations CMS Care Compare 2
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Mercy Hospital South
Acute Care Hospitals · Saint Louis, MOParkland Health Center
Acute Care Hospitals · Farmington, MOPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 63128 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
Reported Quality Measures
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.
SAINT LOUIS, MO 63128
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 Lee Demertzis's NPI number?
The NPI number for Lee Demertzis is 1831298827. It was assigned to this individual provider in the NPPES registry on September 22, 2006.
Where is Lee Demertzis located?
Lee Demertzis practices at 10010 Kennerly Rd, Saint Louis, MO 63128. The listed phone number is (314) 317-0600.
What is Lee Demertzis's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Critical Care Medicine, with taxonomy code 207RC0200X.
Is Lee Demertzis enrolled in Medicare?
Yes. Lee Demertzis 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 organizations bill Medicare for Lee Demertzis's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Lee Demertzis reassigns Medicare benefits to 2 organizations: Mercy Clinic Adult Critical Care, LLC (Saint Louis, MO) and Southeastern Physician Services PC (Oak Ridge, TN). 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 Lee Demertzis's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Lee Demertzis accept?
Health plans from Anthem Blue Cross and Blue Shield list Lee Demertzis 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 Lee Demertzis affiliated with any hospitals?
According to CMS data, Lee Demertzis is affiliated with Mercy Hospital South and Parkland Health Center.
When was this NPI record last updated?
The NPPES record for Lee Demertzis was last updated on March 10, 2015. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 years 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.
# Dr. Lee Michael Demertzis, MD · NPI 1831298827
Critical Care Medicine physician in Saint Louis, Missouri. Individual provider, active in the CMS NPPES registry since September 22, 2006.
## Identity
- **NPI:** 1831298827 (Entity type: Individual)
- **Enumerated:** September 22, 2006
- **Primary specialty:** Internal Medicine - Critical Care Medicine · taxonomy 207RC0200X
- **State license:** 2006001553 (Missouri)
- **Sole proprietor:** No
## Practice location
- **Address:** 10010 KENNERLY RD, Saint Louis, MO 63128-2106
- **Phone:** (314) 317-0600 · **Fax:** (314) 317-0606
## 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:** 2 organizations under Medicare reassignment (form CMS-855R): Mercy Clinic Adult Critical Care, LLC (NPI 1730119421, Saint Louis, MO); Southeastern Physician Services PC (NPI 1083835441, Oak Ridge, TN) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Emory University School Of Medicine, class of 2004
## Record status
- **NPPES last updated:** March 10, 2015
- **Other identifiers:** Medicare PIN 139000092 (MO); Medicare UPIN I71105; Medicaid 1831298827 (MO)
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Source: [NPI Profile](https://npiprofile.com/npi/1831298827) · Data from the CMS NPPES public registry.