Quick answers
- Does Corey L. Farnum accept Medicare assignment?
- Yes. Medicare's clinician data says Corey L. Farnum accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Corey L. Farnum see?
- In 2024, CMS data shows 222 Original Medicare patients and 241 services for Corey L. Farnum. This counts Original Medicare only and measures volume, not quality.
- What is Corey L. Farnum's NPI number?
- 1881707834. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Corey L. Farnum, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 222 |
|---|---|
| Services billed to Medicare | 241 |
| Different services or procedures | 33 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Anesthesia for lens surgery (00142)107 services
- Anesthesia for other procedure on urinary system through urethra (00910)21 services
- Anesthesia for other procedure on skin, muscles, or nerves of head, neck, and upper back (00300)14 services
- Anesthesia for other procedure on eye (00140)13 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol68%
- High blood pressure63%
- Arthritis50%
- Diabetes22%
- Depression18%
- Chronic kidney disease18%
Practice locations
Addresses where Corey L. Farnum is enrolled with Medicare (CMS data updated October 2, 2026).
- 990 4th St SW, Mason City Ambulatory Ct LLCMason City, IA 50401 (641) 494‑2000
Group practices
Medicare enrollment lists Corey L. Farnum as a member of this group (CMS data updated October 2, 2026).
- Mason City Ambulatory Surgery Center, LLC14 clinicians in the group
Specialties
Find other clinicians: Certified Registered Nurse Anesthetist (CRNA), Iowa →
Other nurse anesthetists in Mason City
Clinicians with the same Medicare primary specialty in Mason City, IA — not a recommendation.
Other clinicians in Mason City Ambulatory Surgery Center, LLC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | CNA |
|---|---|
| Graduation year | 2004 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1881707834 |
| 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
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- 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