DR. ALEXANDER GAYLE PARKER MD
NPI 1689177743
Emergency Medicine in Festus, MO
About Dr. Alexander Gayle Parker Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. ALEXANDER GAYLE PARKER MD (NPI 1689177743) is an individual emergency medicine provider in Festus, Missouri, licensed in Missouri (2021047265) and active in the NPI registry since March 2018. He is enrolled in Medicare PECOS, is affiliated with Mercy Hospital Jefferson, and maintains 2 additional practice locations.
NPPES Registry Identity
Specialties & Licenses
Secondary Practice Locations 2
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. Alexander Gayle Parker 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
5Medicare enrollment records show Alexander Parker reassigns Medicare billing to 5 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Festus, MO 63028
- Reassigned Medicare billing, Missouri enrollment
- 118 clinicians in this Medicare group
Saint Louis, MO 63128
- Reassigned Medicare billing, Missouri enrollment
- 186 clinicians in this Medicare group
Saint Louis, MO 63141
- Reassigned Medicare billing, Missouri enrollment
- 241 clinicians in this Medicare group
Washington, MO 63090
- Reassigned Medicare billing, Missouri enrollment
- 178 clinicians in this Medicare group
Alton, IL 62002
- Reassigned Medicare billing, Missouri enrollment
- 343 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 3
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
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Mercy Hospital Jefferson
Acute Care Hospitals · Festus, MOPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 63028 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.
FESTUS, MO 63028
FESTUS, MO 63028
FESTUS, MO 63028
FESTUS, MO 63028
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 Alexander Parker's NPI number?
The NPI number for Alexander Parker is 1689177743. It was assigned to this individual provider in the NPPES registry on March 15, 2018.
Where is Alexander Parker located?
Alexander Parker practices at 1400 Us Highway 61, Festus, MO 63028. The listed phone number is (636) 933-1000.
What is Alexander Parker's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Alexander Parker enrolled in Medicare?
Yes. Alexander Parker 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 Alexander Parker's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Alexander Parker reassigns Medicare benefits to 5 organizations: Mercy Hospital Jefferson (Festus, MO), Mercy Hospital South (Saint Louis, MO), Mercy Hospitals East Communities (Saint Louis, MO), Mercy Hospitals East Communities (Washington, MO) and Southeastern Emergency Physicians Of Memphis LLC (Alton, IL). 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 Alexander Parker's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is Alexander Parker affiliated with any hospitals?
According to CMS data, Alexander Parker is affiliated with Mercy Hospital Jefferson.
When was this NPI record last updated?
The NPPES record for Alexander Parker was last updated on June 13, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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. Alexander Gayle Parker, MD · NPI 1689177743
Emergency Medicine physician in Festus, Missouri. Individual provider, active in the CMS NPPES registry since March 15, 2018.
## Identity
- **NPI:** 1689177743 (Entity type: Individual)
- **Enumerated:** March 15, 2018
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** 2021047265 (Missouri)
- **Sole proprietor:** No
## Practice location
- **Address:** 1400 US HIGHWAY 61, Festus, MO 63028-4100
- **Phone:** (636) 933-1000
## 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:** 5 organizations under Medicare reassignment (form CMS-855R): Mercy Hospital Jefferson (NPI 1508859661, Festus, MO); Mercy Hospital South (NPI 1568481984, Saint Louis, MO); Mercy Hospitals East Communities (NPI 1427098169, Saint Louis, MO); Mercy Hospitals East Communities (NPI 1104912997, Washington, MO); Southeastern Emergency Physicians Of Memphis LLC (NPI 1437105277, Alton, IL) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2020
## Record status
- **NPPES last updated:** June 13, 2024
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Source: [NPI Profile](https://npiprofile.com/npi/1689177743) · Data from the CMS NPPES public registry.