William Chao, M.D.
NPI 1922063205 · Neonatal-Perinatal Medicine Physician · Saint Louis, MO
Enrolled with Medicare as Order and Referring Only - Pediatric Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Chao, M.D. is a Neonatal-Perinatal Medicine Physician provider in Saint Louis, MO (NPI 1922063205).
Provider details
- NPI number
- 1922063205
- Entity type
- Individual
- Primary specialty
- Neonatal-Perinatal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- License
- R9BOO (MO)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-04-19
- Last updated
- 2007-07-08
Frequently asked questions
- What is William Chao's NPI number?
- William Chao's National Provider Identifier (NPI) is 1922063205, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Chao's specialty?
- William Chao is listed in the NPPES registry with a primary specialty of Neonatal-Perinatal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Chao located?
- William Chao's practice location on file with NPPES is 615 S New Ballas Rd, Saint Louis, MO 63141-8221.
- What is William Chao's phone number?
- The practice phone number listed in the NPPES registry for William Chao is (314) 251-6450.
- Does William Chao accept Medicare?
- William Chao is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Chao's NPI active?
- Yes — William Chao's NPI (1922063205) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.