What is Leon Gussow's NPI number?

Leon Gussow's National Provider Identifier (NPI) is 1265585863, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.

What is Leon Gussow's specialty?

Leon Gussow is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).

Where is Leon Gussow located?

Leon Gussow's practice location on file with NPPES is 1740 W Taylor St, Chicago, IL 60612-7232.

What is Leon Gussow's phone number?

The practice phone number listed in the NPPES registry for Leon Gussow is (312) 704-2885.

Is Leon Gussow's NPI active?

Yes — Leon Gussow's NPI (1265585863) is active in the NPPES registry as of the last update on 2025-09-11.

IndividualActive

Leon Gussow, M.D.

NPI 1265585863 · Internal Medicine Physician · Chicago, IL

Leon Gussow, M.D. is a Internal Medicine Physician provider in Chicago, IL (NPI 1265585863).

Provider details

NPI number: 1265585863
Entity type: Individual
Primary specialty: Internal Medicine PhysicianAllopathic & Osteopathic Physicians
Credential: M.D.
Sex: Male
Sole proprietor: No

Specialties & taxonomies

Internal Medicine PhysicianPrimary207R00000X
Allopathic & Osteopathic Physicians
Emergency Medicine Physician207P00000X
Allopathic & Osteopathic Physicians

Profile Score

Detailed profile(83/100 index)

A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.

Registry tenure38% of score
19 yrs in NPPES registry
Profile completeness38% of score
83% 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

1740 W Taylor St

Dept 3466

Chicago, IL 60612-7232

Phone: (312) 704-2885

Fax: (312) 704-2737

Street-level locationGet directions

More IL providers

Mailing address

710 W Buena Ave

Chicago, IL 60613-2222

Enumerated: 2007-01-19
Last updated: 2025-09-11

Frequently asked questions

What is Leon Gussow's NPI number?: Leon Gussow's National Provider Identifier (NPI) is 1265585863, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
What is Leon Gussow's specialty?: Leon Gussow is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
Where is Leon Gussow located?: Leon Gussow's practice location on file with NPPES is 1740 W Taylor St, Chicago, IL 60612-7232.
What is Leon Gussow's phone number?: The practice phone number listed in the NPPES registry for Leon Gussow is (312) 704-2885.
Is Leon Gussow's NPI active?: Yes — Leon Gussow's NPI (1265585863) is active in the NPPES registry as of the last update on 2025-09-11.

Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.