William Grass, ARNP
William Grass, ARNP is a Critical Care Medicine Nurse Practitioner in Creve Coeur, MO, registered under NPI 1407854383.
Getting there
The practice address on file is 10 BARNES WEST DR, Creve Coeur, MO 63141. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| ARNP9207097 | FL | Critical Care Medicine Nurse Practitioner primary |
This provider holds licence ARNP9207097 issued in FL. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Nurse Practitioner
- PAC ID
- 2264494988
- Enrollment ID
- I20041103000924
Medicare enrolment is recorded as approved under the provider type Practitioner - Nurse Practitioner. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Critical Care Medicine covers
Definition to come... NUCC Health Care Provider Taxonomy, code 363LC0200X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1407854383 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 13, 2005 |
| Last updated | Jul 30, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | ARNP |
| Practice address |
10 BARNES WEST DR Creve Coeur, MO 63141 (314) 996-8270 |
| Mailing address |
1 BARNES JEWISH HOSPITAL PLZ Saint Louis, MO 63110 |
| Other identifiers |
Y061EY
· Other (FL) 308331400 · Medicaid (FL) |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 4 | 0 | 7 | 8 | 5 | 4 | 3 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 0 | 7 | 7 | 5 | 8 | 3 | 7 |
Sum = 67 · next multiple of 10 = 70 · check digit = 3 · actual last digit = 3
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.