DR. TIMOTHY JOHN WILLIAMS MD
NPI 1699036731
Internal Medicine in Saint Louis, MO
About Dr. Timothy John Williams Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. TIMOTHY JOHN WILLIAMS MD (NPI 1699036731) is an individual internal medicine provider in Saint Louis, Missouri, licensed in Missouri (2016020999) and active in the NPI registry since June 2012. He is enrolled in Medicare PECOS, is affiliated with Mercy Hospital St Louis, and is a graduate of University Of Cincinnati College Of Medicine (2012).
NPPES Registry Identity
Specialties & Licenses 2
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
Dr. Timothy John Williams 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
7Medicare enrollment records show Timothy Williams reassigns Medicare billing to 7 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
- 435 clinicians in this Medicare group
Saint Louis, MO 63141
- Reassigned Medicare billing, Missouri enrollment
- 326 clinicians in this Medicare group
Saint Louis, MO 63141
- Reassigned Medicare billing, Missouri enrollment
- 611 clinicians in this Medicare group
Saint Louis, MO 63110
- Reassigned Medicare billing, Missouri enrollment
- 1,133 clinicians in this Medicare group
Saint Louis, MO 63128
- Reassigned Medicare billing, Missouri enrollment
- Medicare enrollment name: St Anthonys Physician Organization Hospitalist Services Lc
- 340 clinicians in this Medicare group
Festus, MO 63028
- Reassigned Medicare billing, Missouri enrollment
- 299 clinicians in this Medicare group
Washington, MO 63090
- Reassigned Medicare billing, Missouri enrollment
- 261 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 5
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Mercy Hospital St Louis
Acute Care Hospitals · Saint Louis, MOMercy Hospital Washington
Acute Care Hospitals · Washington, MOMissouri Baptist Medical Center
Acute Care Hospitals · Town And Country, MOChristian Hospital Northeast
Acute Care Hospitals · Saint Louis, MOMercy Hospital Lincoln
Critical Access Hospitals · Troy, MOPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 63141 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.
SAINT LOUIS, MO 63141
SAINT LOUIS, 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 Timothy Williams's NPI number?
The NPI number for Timothy Williams is 1699036731. It was assigned to this individual provider in the NPPES registry on June 5, 2012.
Where is Timothy Williams located?
Timothy Williams practices at 615 S New Ballas Rd, Saint Louis, MO 63141. The listed phone number is (314) 251-6339.
What is Timothy Williams's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Timothy Williams enrolled in Medicare?
Yes. Timothy Williams 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 Timothy Williams's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Timothy Williams reassigns Medicare benefits to 7 organizations: Mercy Hospitals East Communities (Saint Louis, MO), Mercy Clinic Adult Hospitalists - St. Louis, LLC (Saint Louis, MO), Physician Groups Lc (Saint Louis, MO), Washington University (Saint Louis, MO), St Anthonys Physician Organization Hospitalist Services, L.C. (Saint Louis, MO) and 2 more organizations, listed in the Medicare section above. 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 Timothy Williams's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Timothy Williams accept?
Health plans from Anthem Blue Cross and Blue Shield list Timothy Williams 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 Timothy Williams affiliated with any hospitals?
According to CMS data, Timothy Williams is affiliated with Mercy Hospital St Louis, Mercy Hospital Washington, Missouri Baptist Medical Center, Christian Hospital Northeast and Mercy Hospital Lincoln.
When was this NPI record last updated?
The NPPES record for Timothy Williams was last updated on November 3, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 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.
# Dr. Timothy John Williams, MD · NPI 1699036731
Internal Medicine physician in Saint Louis, Missouri. Individual provider, active in the CMS NPPES registry since June 5, 2012.
## Identity
- **NPI:** 1699036731 (Entity type: Individual)
- **Enumerated:** June 5, 2012
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** 2016020999 (Missouri)
- **Sole proprietor:** No
## Practice location
- **Address:** 615 S NEW BALLAS RD, Saint Louis, MO 63141-8221
- **Phone:** (314) 251-6339 · **Fax:** (314) 251-4564
## 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:** 7 organizations under Medicare reassignment (form CMS-855R): Mercy Hospitals East Communities (NPI 1851431738, Saint Louis, MO); Mercy Clinic Adult Hospitalists - St. Louis, LLC (NPI 1841235108, Saint Louis, MO); Physician Groups Lc (NPI 1285664268, Saint Louis, MO); Washington University (NPI 1992746903, Saint Louis, MO); St Anthonys Physician Organization Hospitalist Services, L.C. (NPI 1407216336, Saint Louis, MO); and 2 more · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Cincinnati College Of Medicine, class of 2012
## Record status
- **NPPES last updated:** November 3, 2025
- **Other identifiers:** Medicaid ENROLLED (IL)
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Source: [NPI Profile](https://npiprofile.com/npi/1699036731) · Data from the CMS NPPES public registry.