Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Mr. Seth Ethan Maas, R.D.
Registered Dietitian in Leeds, MA · enumerated 2006.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1104830132
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Registry record
Entity type Individual (Type 1)
Name Mr. Seth Ethan Maas
Credential R.D.
Sex Male
Practice address 421 N Main St, Leeds, MA, 01053
Phone (413) 584-4040
Fax (413) 582-3089
Enumeration date Jul 27, 2006
Last updated in NPPES Apr 7, 2011
Taxonomy & licenses
RD · Registered Dietitian: A nutrition professional credentialed by the Commission on Dietetic Registration.
About the RD 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
What is the NPI number for Seth Maas?
The National Provider Identifier (NPI) for Seth Maas is 1104830132, a Type 1 (individual) record in the CMS NPPES registry.
Where does Seth Maas practice?
The practice location on file with NPPES is in Leeds, MA. Providers can have multiple locations; NPPES lists the primary practice address.
Other providers at this practice address
Browse all → Katherine Walton-Vecchio Physician Assistant · Leeds, MA NPI 1871596247 Jacquelyn Kang Otolaryngology Physician · Leeds, MA NPI 1033104328 Michael Johnson Optometrist · Leeds, MA NPI 1245226976 Alice Abbott Endocrinology, Diabetes & Metabolism Physician · Leeds, MA NPI 1922096205 Paul Haley Psychiatry Physician · Leeds, MA NPI 1295724755 Paul Morrissey Psychiatry Physician · Leeds, MA NPI 1205825304 Faith Weidner Diagnostic Radiology Physician · Leeds, MA NPI 1174505671 George Fuller Geriatric Medicine (Family Medicine) Physician · Leeds, MA NPI 1154306462
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-04-07.