William Gahl, M.D.
William Gahl, M.D. is a Clinical Biochemical Genetics Physician in Bethesda, MD, registered under NPI 1992948582. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 10 CENTER DRIVE MSC 1851 BLDG. 10, ROOM 10C-103, NHGRI, NIH, Bethesda, MD 20892. 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 |
|---|---|---|
| 20993-020 | WI | Clinical Biochemical Genetics Physician primary |
| 20993-020 | WI | Clinical Genetics (M.D.) Physician |
| 20993-020 | WI | Pediatrics Physician |
This provider holds licence 20993-020 issued in WI. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
What Clinical Biochemical Genetics covers
A clinical biochemical geneticist demonstrates competence in performing and interpreting biochemical analyses relevant to the diagnosis and management of human genetic diseases and is a consultant regarding laboratory diagnosis of a broad range of inherited disorders. NUCC Health Care Provider Taxonomy, code 207SG0202X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207SG0202X | Clinical Biochemical Genetics Physician Clinical Biochemical Genetics | 20993-020 | WI | primary |
| 207SG0201X | Clinical Genetics (M.D.) Physician Clinical Genetics (M.D.) | 20993-020 | WI | |
| 208000000X | Pediatrics Physician | 20993-020 | WI |
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 | 1992948582 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 12, 2009 |
| Last updated | Apr 12, 2009 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
10 CENTER DRIVE MSC 1851 BLDG. 10, ROOM 10C-103, NHGRI, NIH Bethesda, MD 20892 (301) 402-2739 Fax (301) 402-2740 |
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 | 9 | 9 | 2 | 9 | 4 | 8 | 5 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 9 | 9 | 2 | 9 | 4 | 7 | 5 | 7 |
Sum = 78 · next multiple of 10 = 80 · check digit = 2 · actual last digit = 2
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.