Guillermo Perez, PA
- Part D claims, 2024
- 94
- Hospital affiliations
- 1
- Industry payments
- $33
- Medical group
- 1
- State license
- 1
- Practice address
- 1101 S Milliken Avenue, Ontario, CA 91761
- Practice phone
- Call (909) 390-2799
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Concentra Urgent Care - Ontario
Urgent Care Center · Ontario, California
Find Guillermo Perez's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Guillermo Perez is a physician assistant in Ontario, California
Guillermo Perez practices at Concentra Urgent Care - Ontario in Ontario, California.
Guillermo Perez's NPI, 1275557506, was assigned on July 27, 2006. Guillermo Perez holds California license PA18456.
- NPI
- 1275557506NPI Registry (opens in a new tab)
- Medicare PAC ID
- 3678576196
- NPI enumeration date
- July 27, 2006
- NPI status
- Active
- Practice phone
- (909) 390-2799
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 46
- Medical school graduation
- 2006
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Guillermo Perez practices at Concentra Urgent Care - Ontario in Ontario, California
Guillermo Perez's primary practice is Concentra Urgent Care - Ontario, at 1101 S Milliken Avenue, Ontario, CA 91761. The practice phone is (909) 390-2799.
- Concentra Urgent Care - Ontario1101 S Milliken Avenue, Ontario, CA 91761Phone(909) 390-2799
Source: Dmand AI Affiliation Data
Guillermo Perez is affiliated with 4 sites of care and 1 medical group
Guillermo Perez's primary practice is Concentra Urgent Care - Ontario in Ontario, California. Guillermo Perez is also affiliated with Sutter Coast Hospital. The medical group on file is Sutter Coast Hospital. Dmand AI also links Guillermo Perez to 1 more group practice or clinic and 1 therapy and rehab clinic, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Guillermo Perez's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Guillermo Perez practices, 4 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Concentra Urgent Care - Ontario | Available with a free account |
| +3 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
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Guillermo Perez is one of 11,482 physician assistants in California
Physician assistant is Guillermo Perez's primary specialty in the NPI Registry, under taxonomy code 363A00000X. Guillermo Perez is board certified in certified physician assistant by the National Commission on Certification of Physician Assistants (NCCPA). Guillermo Perez is licensed in California.
Specialties and state licenses
- Physician assistant, CaliforniaPrimary
Clinical focus
Dmand AI lists acute skin infection, contact dermatitis, minor head injury, minor injury to a limb, upper respiratory infection (URI) and UTI among the conditions Guillermo Perez treats.
Physician assistants near Guillermo Perez
Counts of physician assistants with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Guillermo Perez's patients have a median age of 56
Across all payers, Dmand AI patient panel data puts Guillermo Perez's median patient age at 56, with 57% women.
Guillermo Perez's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 56
Patient panel by sex, all payers
- Women57%
- Men42%
Source: Dmand AI Patient Panel Data
Guillermo Perez wrote 94 Medicare Part D claims in 2024
In 2024, Guillermo Perez wrote 94 Medicare Part D claims for 55 patients. 89% of them were for generic drugs.
Guillermo Perez's Part D claims by kind of drug, 2024
- Generic84 claims89%
- Brand-name and other10 claims11%
Source: Medicare Part D Prescribers - by Provider (CMS), 2024 data
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Guillermo Perez received $33 in industry payments in 2024
CMS Open Payments shows 1 general payment to Guillermo Perez from 1 drug or device company in 2024. Food and beverage make up the largest share, 100% of the total. Boehringer Ingelheim Pharmaceuticals, Inc. paid the most, $33.
Companies that paid Guillermo Perez the most, 2024 to 2024
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Guillermo Perez is board certified in certified physician assistant
- Board certified in certified physician assistant
Source: Dmand AI Professional Profile Data
Sources for Guillermo Perez's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel Data |
| Part D prescribing | Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Guillermo Perez
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Guillermo Perez's NPI number?
Guillermo Perez's NPI number is 1275557506. It was assigned on July 27, 2006, and it is active in the NPI Registry.
What does Guillermo Perez specialize in?
Guillermo Perez is a physician assistant in Ontario, California. The primary specialty in the NPI Registry is Physician Assistant (taxonomy code 363A00000X).
Where does Guillermo Perez practice?
Guillermo Perez practices at 1101 S Milliken Avenue, Ontario, CA 91761. Guillermo Perez's primary practice is Concentra Urgent Care - Ontario in Ontario, California. Dmand AI also links Guillermo Perez to 1 group practice or clinic and 1 therapy and rehab clinic.
What is Guillermo Perez's office phone number?
The practice phone on file for Guillermo Perez is (909) 390-2799.
What is Guillermo Perez's medical license number?
Guillermo Perez holds California license PA18456.
Which hospitals is Guillermo Perez affiliated with?
Guillermo Perez is affiliated with Sutter Coast Hospital.
What medical group is Guillermo Perez part of?
Guillermo Perez is linked to Sutter Coast Hospital.
Is Guillermo Perez board certified?
Yes. Guillermo Perez is board certified in certified physician assistant by the National Commission on Certification of Physician Assistants (NCCPA).
Has Guillermo Perez received payments from drug or device companies?
CMS Open Payments shows $33 in general payments to Guillermo Perez from 1 company from 2024 to 2024. The largest total came from Boehringer Ingelheim Pharmaceuticals, Inc.
How long has Guillermo Perez been practicing?
Guillermo Perez graduated from medical school in 2006, 20 years ago.
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