Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Helen P. Mastro, RD

Registered Dietitian in Somerville, MA · enumerated 2006.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1730152638

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Registry record

Entity type Individual (Type 1)

Name Helen P. Mastro

Credential RD

Sex Female

Practice address 40 Holland St, Somerville, MA, 02144

Phone (617) 629-6287

Enumeration date Feb 10, 2006

Last updated in NPPES Oct 28, 2020

Taxonomy & licenses

133V00000X Registered Dietitian Dietary & Nutritional Service Providers · License 861 (MA) Primary

RD · Registered Dietitian: A nutrition professional credentialed by the Commission on Dietetic Registration. About the RD credential

Other identifiers

Identifier	Type	State	Issuer
LD0098	Other	MA	BLUE CROSS
PQ188	Other	MA	HARVARD PILGRIM
0015227	Other	MA	NEIGHBORHOOD HEALTH PLAN
680078	Other	MA	TUFTS HEALTH PLAN

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.

Read the full guide → Validate an NPI →

Frequently asked questions

What specialty is Helen Mastro?

Helen Mastro is registered in NPPES with the primary taxonomy of Registered Dietitian. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2020-10-28.