Dr. Marlene Amy Ostby, D.D.S., M.S.
Dr. Marlene Amy Ostby is a Orthodontics and Dentofacial Orthopedics Dentistry provider (Dentist) practicing in Billings, MT, registered in the NPPES registry with NPI 1104022607 since 2007. The credential DDS stands for Doctor of Dental Surgery. Practices at Advanced Therapy Clinic LLC (listed at the same practice address in NPPES).
✓ Active NPI ✓ Valid NPI checksum Sole proprietor
| NPI | 1104022607 |
|---|---|
| Entity type | Individual (Type 1) |
| Name | Dr. Marlene Amy Ostby |
| Credential | D.D.S., M.S. |
| Sex | Female |
| Practice address | Billings, MT, 59102 |
| Phone | 4062596774 |
| Fax | 4066576576 |
| Enumeration date | 2007-06-22 |
| Last updated in NPPES | 2011-06-06 |
Street address withheld — NPPES sole-proprietor addresses can be home addresses. See our data policy.
Taxonomy & licenses
| Taxonomy code | Specialty | Primary | License | State |
|---|---|---|---|---|
| 1223X0400X | Orthodontics and Dentofacial Orthopedics Dentistry | Secondary | 21290 | TX |
| 1223X0400X | Orthodontics and Dentofacial Orthopedics Dentistry | Primary | 2336 | MT |
DDS — Doctor of Dental Surgery: A licensed dentist; DDS and DMD are equivalent dental degrees. About the DDS credential
Copy-ready billing details
Provider: Marlene Ostby, D.D.S., M.S. NPI: 1104022607 Taxonomy: 1223X0400X (Orthodontics and Dentofacial Orthopedics Dentistry) Address: Billings, MT, 59102
Other providers at this practice address
| NPI | Name | Type | Specialty | Location |
|---|---|---|---|---|
| 1194097840 | Janelle Smith | Individual | Speech-Language Pathologist | Billings, MT |
| 1265898696 | Advanced Therapy Clinic LLC | Organization | Speech-Language Pathologist | Billings, MT |
| 1194233122 | Shelbi Gragg | Individual | Speech-Language Pathologist | Billings, MT |
| 1154886299 | Rose Reyling | Individual | Speech-Language Pathologist | Billings, MT |
| 1912538083 | Madison Cornelia | Individual | Occupational Therapist | Billings, MT |
| 1144843905 | Alexis Egan | Individual | Occupational Therapist | Billings, MT |
| 1033734819 | Mckenzie Frisk | Individual | Behavior Technician | Billings, MT |
| 1134734015 | Susanna Megorden | Individual | Speech-Language Pathologist | Billings, MT |
Verify this record
Cross-check NPI 1104022607 against the authoritative CMS record: view Dr. Marlene Amy Ostby on the official NPPES registry .
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 or validate an NPI number.
Frequently asked questions
Is NPI 1104022607 active?
How do I verify Marlene Ostby's NPI record?
Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2011-06-06.