Guillermo Ares, MD
NPI 1942542105 · Pediatric Surgery Physician · Maywood, IL
Enrolled with Medicare as Practitioner - General Surgery · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Guillermo Ares, MD is a Pediatric Surgery Physician provider in Maywood, IL (NPI 1942542105).
Provider details
- NPI number
- 1942542105
- Entity type
- Individual
- Primary specialty
- Pediatric Surgery PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
13 yrs in NPPES registry
- Profile completeness33% of score
83% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$23 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2013-03-25
- Last updated
- 2022-10-14
- Certified
- 2022-10-14
Frequently asked questions
- What is Guillermo Ares's NPI number?
- Guillermo Ares's National Provider Identifier (NPI) is 1942542105, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Guillermo Ares's specialty?
- Guillermo Ares is listed in the NPPES registry with a primary specialty of Pediatric Surgery Physician (Allopathic & Osteopathic Physicians).
- Where is Guillermo Ares located?
- Guillermo Ares's practice location on file with NPPES is 2160 S 1st Ave, Maywood, IL 60153-3328.
- What is Guillermo Ares's phone number?
- The practice phone number listed in the NPPES registry for Guillermo Ares is (708) 216-9000.
- Does Guillermo Ares accept Medicare?
- Guillermo Ares is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Guillermo Ares's NPI active?
- Yes — Guillermo Ares's NPI (1942542105) is active in the NPPES registry as of the last update on 2022-10-14.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.