Physician Profile
Karl C. Sonntag, MD
Unclaimed ProfileAbout Dr. Sonntag
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Specialty
Credentials & Licensing
License numbers are what the provider reported to NPPES when the NPI was issued or updated. NPPES does not verify licensure; confirm current standing with the state licensing board.
Contact Information
- (314) 768-8373
- Email not available
Practice Locations
6420 CLAYTON RD
Saint Louis, MO 63117
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Other internists at this location 5
Same specialty, same street address — most likely the same department or group.
Related specialists at this location 2
Clinically related specialties at the same address — the people this provider most likely works alongside.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
More connections — 8 related providers in 1 group
Common questions
What does Dr. Sonntag specialize in?
Dr. Sonntag is an internist in Saint Louis, MO. That is the designation recorded for this NPI in the federal registry, where it is listed as “Internal Medicine”.
NPI registry
Where is Dr. Sonntag located?
Dr. Sonntag is listed at 6420 Clayton Rd, Saint Louis, MO 63117. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
What is Dr. Sonntag's phone number?
The number on file is (314) 768-8373. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
What is Dr. Sonntag's NPI number?
Dr. Sonntag's National Provider Identifier is 1164029146. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
How long has Dr. Sonntag been practicing?
Dr. Sonntag has 6+ years experience. Registered with an NPI since 2020. National Provider Identifiers only began in 2005, so a provider who qualified earlier may have practiced for longer than this.
NPI registry
Has Dr. Sonntag confirmed this information?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Sonntag. If this is you, claiming it is free.
Guide.md
Provider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.