Quick answers
- Which hospitals does Thoo Tan work at?
- Medicare's official clinician data lists Thoo Tan at 3 hospitals: Hancock County Health System, Kossuth Regional Health Center and MercyOne North Iowa Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Thoo Tan see patients?
- Medicare's clinician data lists 7 practice locations, including Mason City, IA, Algona, IA and New Hampton, IA. Call before your visit to confirm the address.
- What is Thoo Tan's specialty?
- Medicare lists Obstetrics/Gynecology as the primary specialty, and also Emergency Medicine.
- Does Thoo Tan accept Medicare assignment?
- Medicare's clinician data says Thoo Tan may accept Medicare assignment (as of 2026-10-02). Ask the office whether they accept it for your visit.
- What is the phone number for Thoo Tan?
- (641) 428-7847, as listed in official Medicare / NPI Registry data.
- What is Thoo Tan's NPI number?
- 1104857127. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Thoo Tan works
Medicare's Facility Affiliation Data lists Thoo Tan at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Hancock County Health SystemBritt, IA · Critical Access Hospital · CCN 161307
- Kossuth Regional Health CenterAlgona, IA · Critical Access Hospital · CCN 161353
- MercyOne North Iowa Medical CenterMason City, IA · Acute Care Hospital · CCN 160064
Practice locations
Addresses where Thoo Tan is enrolled with Medicare (CMS data updated 2026-10-02). The first 5 of 7; the Medicare profile lists all.
- 1000 4th St SWMason City, IA 50401
- 1010 4th St SWMason City, IA 50401
- 1010 4th St SW, 105 Mercyone North Iowa Neurosurgery CareMason City, IA 50401 (641) 428‑7847
- 1515 S Phillips StAlgona, IA 50511
- 1519 S Phillips StAlgona, IA 50511
Group practices
Medicare enrollment lists Thoo Tan as a member of these groups (CMS data updated 2026-10-02).
- North Iowa Mercy Clinics302 clinicians in the group
- Kossuth Regional Health Center25 clinicians in the group
- Mercy Medical Center New Hampton20 clinicians in the group
Specialties
- Obstetrics/Gynecologyprimary
- Emergency Medicinealso
Other OB-GYNs in Mason City
Clinicians with the same Medicare primary specialty in Mason City, IA — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Graduation year | 1990 |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1104857127 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians