Catherine Johnson, MD FACEP, ABOM, MSCP
Catherine Johnson, MD FACEP, ABOM, MSCP is an Obesity Medicine (Preventive Medicine) Physician in Clarendon Hills, IL, registered under NPI 1083609218. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 23 WALKER AVE, Clarendon Hills, IL 60514. 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 |
|---|---|---|
| 36107532 | IL | Obesity Medicine (Preventive Medicine)… primary |
| 01056490 | IN | Emergency Medicine Physician |
| 036107532 | IL | Emergency Medicine Physician |
Licences are recorded in 2 states: IL, IN. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
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.
Licensed in 2 states
This provider holds licences in 2 states: Illinois and Indiana. The practice address on file is in Clarendon Hills, IL, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
- Licence
- 36107532
- Specialty
- Obesity Medicine (Preventive Medicine)…
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Obesity Medicine covers
A physician who specializes in the treatment of obesity demonstrates competency in and a thorough understanding of the treatment of obesity and the genetic, biologic, environmental, social, and behavioral factors that contribute to obesity. The obesity medicine physician employs therapeutic interventions including diet, physical activity, behavioral change, and pharmacotherapy. The obesity medicine physician utilizes a comprehensive approach, and may include additional resources such as dietitians, exercise physiologists, mental health professionals and bariatric surgeons as indicated to achieve optimal results. Additionally, the obesity medicine physician maintains competency in providing pre- peri- and post-surgical care of bariatric surgery patients, promotes the prevention of obesity, and advocates for those who suffer from obesity. NUCC Health Care Provider Taxonomy, code 2083B0002X
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 | |
|---|---|---|---|---|
| 2083B0002X | Obesity Medicine (Preventive Medicine) Physician Obesity Medicine | 36107532 | IL | primary |
| 207P00000X | Emergency Medicine Physician | 01056490 | IN | |
| 207P00000X | Emergency Medicine Physician | 036107532 | IL |
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 | 1083609218 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 14, 2005 |
| Last updated | Apr 14, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD FACEP, ABOM, MSCP |
| Practice address |
23 WALKER AVE Clarendon Hills, IL 60514 (312) 343-4342 Fax (312) 736-9556 |
| Mailing address |
256 HOLMES AVE Clarendon Hills, IL 60514 |
| Other identifiers |
200430170
· Medicaid (IN) |
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 | 0 | 8 | 3 | 6 | 0 | 9 | 2 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 7 | 3 | 3 | 0 | 9 | 2 | 2 |
Sum = 52 · next multiple of 10 = 60 · check digit = 8 · actual last digit = 8
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.