Dr. Mark L. Horowitz, MD
- Industry payments
- $18
- Affiliated sites
- 1
- Medical group
- 1
- State licenses
- 2
- Year NPI issued
- 2006
- Practice address
- 100 Woods Rd, Valhalla, NY 10595
- Practice phone
- Call (914) 493-2961
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Westchester Medical Center
Valhalla, New York
Find Dr. Horowitz'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.
Dr. Mark L. Horowitz is a pediatrician in Valhalla, New York
Dr. Horowitz practices at Westchester Medical Center in Valhalla, New York.
Dr. Horowitz's NPI, 1477649853, was assigned on October 5, 2006. Dr. Horowitz graduated from New York Medical College in 1977. Dr. Horowitz holds New York license 135749-1.
- NPI
- 1477649853NPI Registry (opens in a new tab)
- NPI enumeration date
- October 5, 2006
- NPI status
- Active
- Practice phone
- (914) 493-2961
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Medical school graduation
- 1977
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Practice Data
Dr. Mark L. Horowitz practices at Westchester Medical Center in Valhalla, New York
Dr. Horowitz's primary practice is Westchester Medical Center, at 100 Woods Rd, Valhalla, NY 10595 in Westchester County. The practice phone is (914) 493-2961.
- Westchester Medical Center100 Woods Rd, Valhalla, NY 10595 · Westchester CountyPhone(914) 493-2961
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. Mark L. Horowitz is affiliated with 2 sites of care and 1 medical group
Dr. Horowitz's primary practice is Westchester Medical Center in Valhalla, New York. Dmand AI also links Dr. Horowitz to 1 group practice or clinic and 1 medical group, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Mark L. Horowitz's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Horowitz practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Westchester Medical Center | Available with a free account |
| +1 more site and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
For health IT teams
Dmand AI maps EHR vendors, IT decision makers and buying committees across each health system and 6.2K+ hospitals, with verified contacts in the same login.
Dr. Mark L. Horowitz is one of 4,313 pediatricians in New York
Pediatrics is Dr. Horowitz's primary specialty in the NPI Registry, under taxonomy code 208000000X. Dmand AI has Dr. Horowitz's licenses on file in 2 states: New York and New Jersey.
Specialties and state licenses
- Pediatrics, New YorkPrimary
- New Jersey license
Pediatricians near Dr. Horowitz
Counts of pediatricians 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
Dr. Mark L. Horowitz's patients have a median age of 23
Across all payers, Dmand AI patient panel data puts Dr. Horowitz's median patient age at 23, with 75% women.
Dr. Horowitz's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 23
Patient panel by sex, all payers
- Women75%
- Men25%
Source: Dmand AI Patient Panel Data
Dr. Mark L. Horowitz received $18 in industry payments in 2017
CMS Open Payments shows 1 general payment to Dr. Horowitz from 1 drug or device company in 2017. Speaker and faculty fees make up the largest share, 100% of the total. Sanofi Pasteur Inc. paid the most, $18.
Companies that paid Dr. Horowitz the most, 2017 to 2017
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Mark L. Horowitz graduated from New York Medical College
Dr. Horowitz graduated from New York Medical College in 1977.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Mark L. Horowitz'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 | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand AI Affiliation Data |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel Data |
| 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 Dr. Mark L. Horowitz
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Mark L. Horowitz's NPI number?
Dr. Mark L. Horowitz's NPI number is 1477649853. It was assigned on October 5, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Mark L. Horowitz?
Dr. Mark L. Horowitz is a pediatrician in Valhalla, New York. The primary specialty in the NPI Registry is Pediatrics Physician (taxonomy code 208000000X).
Where does Dr. Mark L. Horowitz practice?
Dr. Horowitz practices at 100 Woods Rd, Valhalla, NY 10595. Dr. Horowitz's primary practice is Westchester Medical Center in Valhalla, New York. Dmand AI also links Dr. Horowitz to 1 group practice or clinic and 1 medical group.
What is Dr. Mark L. Horowitz's office phone number?
The practice phone on file for Dr. Horowitz is (914) 493-2961.
What is Dr. Mark L. Horowitz's medical license number?
Dr. Horowitz holds New York license 135749-1, one of the licenses on file in 2 states.
Which states has Dr. Mark L. Horowitz been licensed in?
Dmand AI has state licenses on file for Dr. Horowitz in New York and New Jersey.
Where did Dr. Mark L. Horowitz go to medical school?
Dr. Horowitz graduated from New York Medical College in 1977.
Has Dr. Mark L. Horowitz received payments from drug or device companies?
CMS Open Payments shows $18 in general payments to Dr. Horowitz from 1 company from 2017 to 2017. The largest total came from Sanofi Pasteur Inc.
How long has Dr. Mark L. Horowitz been practicing?
Dr. Horowitz graduated from medical school in 1977, 49 years ago.
Selling to pediatrics practices?
See pediatricians in New York by site of care and group
Find the practices, groups and hospitals they work with, and the right people to contact at each.
- 30 days free
- Self-serve
- No credit card