DR. JOHN SPENCER MAYS MD
NPI 1083108062
General Practice in Saint Louis, MO
About Dr. John Spencer Mays Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. JOHN SPENCER MAYS MD (NPI 1083108062) is an individual general practice provider in Saint Louis, Missouri, licensed in Missouri (2020001817) and active in the NPI registry since June 2018. He is enrolled in Medicare PECOS, is affiliated with Alton Memorial Hospital, and is a graduate of University Of Tennessee, Hsc, College Of Medicine (2018).
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 and accepts Medicare assignment
Dr. John Spencer Mays 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 Reassignment
Medicare enrollment records show John Mays reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Saint Louis, MO 63141
- Reassigned Medicare billing, Missouri enrollment
- 611 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 13
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 5
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Alton Memorial Hospital
Acute Care Hospitals · Alton, ILBarnes Jewish Hospital
Acute Care Hospitals · Saint Louis, MOMissouri Baptist Medical Center
Acute Care Hospitals · Town And Country, MOBarnes-Jewish West County Hospital
Acute Care Hospitals · Creve Coeur, MOChristian Hospital Northeast
Acute Care Hospitals · Saint Louis, MOReferred Medical Equipment & Supplies CMS DME claims 2
Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.
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 63141
SAINT LOUIS, MO 63141
SAINT LOUIS, MO 63141
SAINT LOUIS, MO 63141
SAINT LOUIS, MO 63141
SAINT LOUIS, MO 63141
CREVE COEUR, MO 63141
CREVE COEUR, MO 63141
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 John Mays's NPI number?
The NPI number for John Mays is 1083108062. It was assigned to this individual provider in the NPPES registry on June 21, 2018.
Where is John Mays located?
John Mays practices at 1044 N Mason Rd Div Im General Med, Ste 330, Saint Louis, MO 63141. The listed phone number is (314) 996-8103.
What is John Mays's specialty?
The primary specialty registered for this NPI is General Practice with taxonomy code 208D00000X.
Is John Mays enrolled in Medicare?
Yes. John Mays 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 John Mays's services?
According to the CMS Revalidation Reassignment List (October 2026 release), John Mays reassigns Medicare benefits to Physician Groups Lc (Saint Louis, MO). 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 John Mays's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does John Mays accept?
Health plans from Cox HealthPlans and UnitedHealthcare list John Mays 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 John Mays affiliated with any hospitals?
According to CMS data, John Mays is affiliated with Alton Memorial Hospital, Barnes Jewish Hospital, Missouri Baptist Medical Center, Barnes-Jewish West County Hospital and Christian Hospital Northeast.
When was this NPI record last updated?
The NPPES record for John Mays was last updated on September 1, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 49 days 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. John Spencer Mays, MD · NPI 1083108062
General Practice physician in Saint Louis, Missouri. Individual provider, active in the CMS NPPES registry since June 21, 2018.
## Identity
- **NPI:** 1083108062 (Entity type: Individual)
- **Enumerated:** June 21, 2018
- **Primary specialty:** General Practice · taxonomy 208D00000X
- **State license:** 2020001817 (Missouri)
- **Sole proprietor:** No
## Practice location
- **Address:** 1044 N MASON RD, DIV IM GENERAL MED, STE 330, Saint Louis, MO 63141-6431
- **Phone:** (314) 996-8103 · **Fax:** (314) 996-3230
## 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:** Physician Groups Lc (NPI 1285664268, Saint Louis, MO), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Tennessee, Hsc, College Of Medicine, class of 2018
## Record status
- **NPPES last updated:** September 1, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1083108062) · Data from the CMS NPPES public registry.