Quick answers
- Does James L. Williams Ii accept Medicare assignment?
- Yes. Medicare's clinician data says James L. Williams Ii accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does James L. Williams Ii see?
- In 2024, CMS data shows 73 Original Medicare patients and 254 services for James L. Williams Ii. This counts Original Medicare only and measures volume, not quality.
- What is James L. Williams Ii's NPI number?
- 1043290620. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for James L. Williams Ii, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 73 |
|---|---|
| Services billed to Medicare | 254 |
| Different services or procedures | 12 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Needle measurement of electrical activity in arm or leg muscles, complete study (95886)93 services
- New patient office or other outpatient visit with straightforward medical decision making, if using time, 15 minutes or more (99202)57 services
- Nerve conduction, 9-10 studies (95911)27 services
- Nerve conduction, 5-6 studies (95909)17 services
- Nerve conduction, 7-8 studies (95910)15 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol75%
- Arthritis75%
- High blood pressure70%
- Ischemic heart disease34%
- Depression26%
- Anxiety23%
Practice locations
Addresses where James L. Williams Ii is enrolled with Medicare (CMS data updated October 2, 2026).
- 121 Saint Lukes Ctr DrChesterfield, MO 63017 (314) 390‑6789
- 12639 Old Tesson RdSaint Louis, MO 63128
- 4701 State Hwy KO Fallon, MO 63368 (636) 441‑3444
- 5200 Executive Centre Pkwy, 300 St. Peters Bone and Joint SurgerySaint Peters, MO 63376 (636) 441‑3444
Group practices
Medicare enrollment lists James L. Williams Ii as a member of these groups (CMS data updated October 2, 2026).
- Signature Medical Group Inc41 clinicians in the group
- St Peters Bone and Joint Surgery Inc26 clinicians in the group
Specialties
Find other Physical Medicine and Rehabilitation doctors in Missouri →
Other rehabilitation doctors in Chesterfield
Clinicians with the same Medicare primary specialty in Chesterfield, MO — not a recommendation.
Other clinicians in Signature Medical Group Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Missouri, Columbia School Of Medicine |
| Graduation year | 1997 (29 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1043290620 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians