Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Dr. Daniel M Horn, MD
Internal Medicine Physician in Waltham, MA · enumerated 2010.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1780903971
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Registry record
Entity type Individual (Type 1)
Name Dr. Daniel M Horn
Credential MD
Sex Male
Practice address 221 Crescent St Ste 202, Waltham, MA, 02453
Phone (866) 849-0692
Enumeration date May 27, 2010
Last updated in NPPES May 26, 2026
Taxonomy & licenses
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 91509 (SC) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 72732 (AZ) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 036.168528 (IL) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License MD.48112 (AL) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License MD24268 (HI) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 35C.001303 (OH) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 251716 (MA) Primary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 2024-01822 (NC) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License ME166617 (FL) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 70584 (TN) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License MD218918 (OR) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 100333 (GA) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License U8885 (TX) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License DR.0072398 (CO) Secondary
207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License MD484408 (PA) Secondary
MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure.
About the MD 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 Daniel Horn?
Daniel Horn is registered in NPPES with the primary taxonomy of Internal Medicine Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
Other providers at this practice address
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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-05-26.