Daniel M. Horn, MD
Internal Medicine Physician · Waltham, MA
Daniel M. Horn, MD is an internal medicine physician with a practice address in Waltham, Massachusetts, and NPI 1780903971, issued on May 27, 2010. Check the license (Massachusetts 251716, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Daniel M. Horn
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- 251716 MA
MD.48112 AL
72732 AZ
DR.0072398 CO
ME166617 FL
and 10 more
Self-reported in NPPES; status is on the state search - Practice location
- 221 Crescent St Ste 202, Waltham, MA 02453
- Phone
- (866) 849-0692
- Enumerated
- May 27, 2010
- Record last updated
- Jun 11, 2026
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 6,825 in Massachusetts → Look up another NPI →
Also registered at 221 Crescent St Ste 202
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Nwanneka AniunohPharmacist1306795182
- Jennifer Colborn, RNRegistered Nurse1548192719
- Patricia Moynihan, RNCase Management Registered Nurse1790515070
- Brenda NamaraPharmacist Clinician (PhC)/ Clinical Pharmacy Specialist1386504157
- Stephanie RicciRegistered Nurse1780414847
- Scott Williams, M.D.Family Medicine Physician1992048334
Verify Daniel M. Horn in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 251716Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
64% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,134 Medicare Part D claims for 268 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.
Most prescribed
- Atorvastatin Calcium149 claims
- Amlodipine Besylate126 claims
- Hydrochlorothiazide54 claims
- Lisinopril50 claims
- Losartan Potassium43 claims
- Metformin Hcl40 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Daniel M. Horn among 6,825 internal medicine physician records in Massachusetts
Daniel M. Horn, MD is one of 6,825 internal medicine physician records with a practice address in Massachusetts. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2010, is newer than 63% of them.
- NPI issued2010 · 63% of these records are older, 35% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileNo · 60% of these records are
- Record last updated2026 · 64% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
32 internal medicine physician records list a practice address in Waltham
They are 32 of the 2,111 NPPES records with a practice address in Waltham, and 6,825 internal medicine physician records in Massachusetts.
All 6,825 in Massachusetts → Every provider in Waltham → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Denise Basow, M.D.Waltham, MA 024531609883255
- Edward Busick, M.D.Waltham, MA 024531467436931
- Rebecca Connor, M.D.Waltham, MA 024531598880379
- Barry Ehrlich, M.D.Waltham, MA 024531710934047
- Wissam Khoory, M.D.Waltham, MA 024531013962430
- Henry Merola, M.D.Waltham, MA 024531902963986
- Mark Shankman, MDWaltham, MA 024531629028709
- Hadia Tirmizi, M.D.Waltham, MA 024531235124249
Common questions
What is Daniel M. Horn, MD's NPI number?
Daniel M. Horn, MD's National Provider Identifier (NPI) is 1780903971, issued on May 27, 2010. An NPI identifies a provider in billing; it is not a license.
Where is Daniel M. Horn, MD located?
The NPPES record lists a practice address at 221 Crescent St Ste 202, Waltham, MA, 02453. Phone: (866) 849-0692. Providers update this record themselves, so call before visiting.
How can I verify Daniel M. Horn, MD's license?
NPPES lists Massachusetts license number 251716, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Daniel M. Horn, MD prescribe under Medicare Part D?
In 2024, Daniel M. Horn, MD had 1,134 Medicare Part D claims for 268 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.