Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Mary Nessan, DENTAL HYGIENIST
Dental Hygienist in Billings, MT · enumerated 2020.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1639789696
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Registry record
Entity type Individual (Type 1)
Name Mary Nessan
Credential DENTAL HYGIENIST
Sex Female
Practice address 123 S 27th St, Billings, MT, 59101
Phone (406) 247-3333
Enumeration date Aug 5, 2020
Last updated in NPPES Sep 25, 2020
Taxonomy & licenses
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 Mary Nessan?
The National Provider Identifier (NPI) for Mary Nessan is 1639789696, a Type 1 (individual) record in the CMS NPPES registry.
Where does Mary Nessan practice?
The practice location on file with NPPES is in Billings, MT. Providers can have multiple locations; NPPES lists the primary practice address.
Other providers at this practice address
Browse all → Carla Cobb Psychiatric Pharmacist · Billings, MT NPI 1285633677 James Guyer Family Medicine Physician · Billings, MT NPI 1962495697 Frank Thompson Family Medicine Physician · Billings, MT NPI 1578557120 Roxanne Fahrenwald Family Medicine Physician · Billings, MT NPI 1104810688 Dale Agner Family Medicine Physician · Billings, MT NPI 1861486490 John Malloy Family Medicine Physician · Billings, MT NPI 1629064845 Myrna Mentikov Physician Assistant · Billings, MT NPI 1750377735 Kathryn Hall Physician Assistant · Billings, MT NPI 1366438285
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2020-09-25.