NPI age
20 years
Enumerated 2005-10-19
● Active
Type 1 · Individual
William D. Ratnoff, M.D.
Ratnoff is 1 of 123 internal medicine providers in Houston and 1 of 749 in Texas.
Primary specialty
Internal Medicine
Plus 3 subspecialties
Licensed in
TX, MT, UT, ND
4 states
Status
Active
No deactivations on record
Last NPPES update
2017-09-19
Source: monthly bulk 2026-05
Sole proprietor
Yes
Solo practice on file
How this provider compares
Across 749 active internal medicine providers in Texas.
NPI age
20 years
↑ 2 yr above median (18 yr)
State licenses
4 states
Top 85% — 15% of peers are multi-state
Subspecialties
0
34% of peers hold subspecialties
NPI lifetime · 2005 → 2026
2005-10Enumerated in NPPES
2005
2026
Where they practice
Practice location
912 Detering St
Houston, TX 770075157
Mailing address
Po Box 27511
Houston, TX 772277511
Specialties
-
Internal Medicine PrimaryAn internist who treats diseases of joints, muscle, bones and tendons. This specialist diagnoses and treats arthritis, back pain, muscle strains, common athletic injuries and "collagen" diseases.
Identifiers
| Type | Value | Notes |
|---|---|---|
| 05 (TX) | 122161100 | |
| 05 (TX) | 043734501 | |
| 05 (TX) | 048525201 | |
| 01 (TX) | 122161101 | FIRSTCARE COMMERCIAL |
| 05 (TX) | 043734504 | |
| 05 (OK) | 100042210A | |
| 01 (TX) | 80736Z | HMO BLUE |
| 01 (TX) | 8B8815 | BLUE CROSS BLUE SHIELD OF TEXAS |
| 01 (NM) | B002 | TRIWEST |
| 01 (NM) | 52501 | PRESBYTERIAN COMMERCIAL |
| 05 (NM) | R8725 | |
| 05 (NM) | 52501 | |
| 01 (TX) | 87231G | BC/BS |
Multi-state credentialing: Licensed in 4 states. Useful context for credentialers building cross-state provider networks.
Practice context
Solo or small practice. No other active providers share this practice address in NPPES. This provider is listed as a sole proprietor.
Recently enumerated nearby: 1 new internal medicine provider has been added in Houston in the last 180 days.
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Request a quote →How to verify this provider
- Confirm the NPI on NPPES.The CMS registry is the system of record. Open NPPES →
- Check the state license is currently active.State licensing boards publish current status; NPPES does not.
- Confirm payer enrollment if billing.NPI presence does not guarantee active enrollment with Medicare, Medicaid, or commercial payers.