WILLIAM GILES STUART MACKENZIE M.D.
NPI 1952744898
Orthopaedic Surgery - Pediatric Orthopaedic Surgery in Wilmington, DE
About William Giles Stuart Mackenzie M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
WILLIAM GILES STUART MACKENZIE M.D. (NPI 1952744898) is an individual pediatric orthopaedic surgery provider in Wilmington, Delaware, licensed in Delaware (C1-0013223) and active in the NPI registry since April 2013. He is enrolled in Medicare PECOS, maintains a secondary practice location in New York, and is a graduate of Other (2013).
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
William Giles Stuart Mackenzie M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignment
Medicare enrollment records show William Mackenzie reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Wilmington, DE 19803
- Reassigned Medicare billing, Delaware and Florida enrollments
- Also billed through NPI 1265585806 (Florida)
- 526 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
WILMINGTON, DE 19803
WILMINGTON, DE 19803
WILMINGTON, DE 19803
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is William Mackenzie's NPI number?
The NPI number for William Mackenzie is 1952744898. It was assigned to this individual provider in the NPPES registry on April 10, 2013.
Where is William Mackenzie located?
William Mackenzie practices at 1600 Rockland Rd, Wilmington, DE 19803. The listed phone number is (302) 651-4200.
What is William Mackenzie's specialty?
The primary specialty registered for this NPI is Orthopaedic Surgery, specializing in Pediatric Orthopaedic Surgery, with taxonomy code 207XP3100X.
Is William Mackenzie enrolled in Medicare?
Yes. William Mackenzie is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organization bills Medicare for William Mackenzie's services?
According to the CMS Revalidation Reassignment List (October 2026 release), William Mackenzie reassigns Medicare benefits to The Nemours Foundation (Wilmington, DE). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for William Mackenzie's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does William Mackenzie accept?
Health plans from Ambetter Health, Ambetter Health of Delaware, Ambetter from NH Healthy Families, Ambetter from Sunflower Health Plan and AmeriHealth Caritas Next and 4 other insurers list William Mackenzie as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
When was this NPI record last updated?
The NPPES record for William Mackenzie was last updated on September 4, 2019. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# William Giles Stuart Mackenzie, M.D. · NPI 1952744898
Pediatric Orthopaedic Surgery physician in Wilmington, Delaware. Individual provider, active in the CMS NPPES registry since April 10, 2013.
## Identity
- **NPI:** 1952744898 (Entity type: Individual)
- **Enumerated:** April 10, 2013
- **Primary specialty:** Orthopaedic Surgery - Pediatric Orthopaedic Surgery · taxonomy 207XP3100X
- **State license:** C1-0013223 (Delaware)
- **Sole proprietor:** No
## Practice location
- **Address:** 1600 ROCKLAND RD, Wilmington, DE 19803
- **Phone:** (302) 651-4200 · **Fax:** (302) 651-4945
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** The Nemours Foundation (NPI 1366594699, Wilmington, DE), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2013
## Record status
- **NPPES last updated:** September 4, 2019
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Source: [NPI Profile](https://npiprofile.com/npi/1952744898) · Data from the CMS NPPES public registry.