Physician Profile
Unclaimed ProfileAbout ONSAGER
David R Onsager is a healthcare provider in Chicago, IL specializing in cardiac surgery. David trained at Rush Medical College of Rush University, graduating in 1988. David is also listed as specializing in thoracic surgery (cardiothoracic).
Summarised automatically from public NPI registry and CMS Medicare data. Not written or reviewed by this provider. Claim this profile to replace it.
Education & Training
Areas of Expertise
Licensing & Certification
Source: NPPES NPI Registry
Contact Information
- (888) 824-0200
- Email not available
Practice Locations
5841 S MARYLAND AVE
Chicago, IL 60637
Procedures Most Often Billed to Medicare
11 services · 11 patients · 1 distinct codes
| Procedure | Type | Code | Services |
|---|---|---|---|
| Coronary artery bypass using artery graft, 1 graft | Procedure | 33533 |
11 |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
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.
Other cardiac surgeons in Chicago 8
Same specialty, same city.
Trained at Rush Medical College of Rush University 2
Other providers in the same specialty who trained at the same institution.
More connections — 15 related providers in 2 groups
Class of 1988 at Rush Medical College of Rush University 8
Providers who graduated from the same medical school in the same year.
Also performs Coronary artery bypass using artery graft, 1 graft 7
Providers in IL who bill this service to Medicare most often.
Common questions
What kind of doctor is Dr. Onsager?
Dr. Onsager is a cardiac surgeon in Chicago, IL. This is the primary taxonomy recorded against the NPI in the federal registry, listed there as “CARDIAC SURGERY”.
NPI registry
What is Dr. Onsager's address?
Dr. Onsager is listed at 5841 S MARYLAND AVE, Chicago, IL 60637. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
How can I make an appointment with Dr. Onsager?
The number on file is (888) 824-0200. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
What is Dr. Onsager's NPI number?
Dr. Onsager's National Provider Identifier is 1396829156. 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
Where did Dr. Onsager train?
Dr. Onsager attended Rush Medical College of Rush University, graduating in 1988. This comes from the CMS National Downloadable File.
CMS public data
How long has Dr. Onsager been practicing?
Dr. Onsager has 38 years experience. Calculated from a graduation year of 1988, reported in the CMS National Downloadable File.
CMS public data
What procedures does Dr. Onsager perform?
According to Medicare billing data, Dr. Onsager performs procedures including coronary artery bypass using artery graft, 1 graft. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Has Dr. Onsager confirmed this information?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Onsager. If this is you, claiming it is free.
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Claim this profileProvider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.