Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Margaret M Gaynor, APRN, CNP
Nurse Practitioner in Mchenry, IL · enumerated 2015.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1164890869
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Registry record
Entity type Individual (Type 1)
Name Margaret M Gaynor
Credential APRN, CNP
Sex Female
Practice address 4309 W Medical Center Dr Ste B301, Mchenry, IL, 60050
Phone (847) 802-7400
Fax (815) 759-4375
Enumeration date Sep 11, 2015
Last updated in NPPES Sep 5, 2024
Taxonomy & licenses
363LG0600X Gerontology Nurse Practitioner Physician Assistants & Advanced Practice Nursing Providers · License 041.256894 (IL) Secondary
363L00000X Nurse Practitioner Physician Assistants & Advanced Practice Nursing Providers · License 209013236 (IL) Primary
APRN · Advanced Practice Registered Nurse: An umbrella credential covering NPs, CRNAs, CNMs, and clinical nurse specialists.
About the APRN credential
What is an NPI number?
A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.
Frequently asked questions
Is this the official NPI registry?
No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.
What specialty is Margaret Gaynor?
Margaret Gaynor is registered in NPPES with the primary taxonomy of Nurse Practitioner. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
Other providers at this practice address
Browse all →Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2024-09-05.