Quick answers
- Does James L. Leenstra accept Medicare assignment?
- Yes. Medicare's clinician data says James L. Leenstra 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 James L. Leenstra see?
- In 2024, CMS data shows 139 Original Medicare patients and 2,369 services for James L. Leenstra. This counts Original Medicare only and measures volume, not quality.
- What is James L. Leenstra's NPI number?
- 1174593982. 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 James L. Leenstra, 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 | 139 |
|---|---|
| Services billed to Medicare | 2,369 |
| Different services or procedures | 31 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Stereoscopic x-ray guidance for localization of target volume for the delivery of radiation therapy (G6002)560 services
- Intensity modulated treatment delivery, single or multiple fields/arcs,via narrow spatially and temporally modulated beams, binary, dynamic mlc, per treatment session (G6015)546 services
- Calculation of radiation therapy dose (77300)200 services
- Continuing radiation therapy consultation per week (77336)144 services
- Radiation treatment management, 5 treatment sessions (77427)125 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).
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)75%
- High cholesterol71%
- High blood pressure68%
- Arthritis32%
- Ischemic heart disease27%
- Chronic kidney disease22%
Hospitals where James L. Leenstra works
Medicare's Facility Affiliation Data lists James L. Leenstra at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Mayo Clinic Health System - Cannon FallsCannon Falls, MN · Critical Access Hospital · Emergency services: listed by Medicare · CCN 241346
- Mayo Clinic Health System in Red WingRed Wing, MN · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 240018
- Mayo Clinic Health System New PragueNew Prague, MN · Critical Access Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 241361
- Mayo Clinic Hospital RochesterRochester, MN · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 240010
- Northfield HospitalNorthfield, MN · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 240014
Practice locations
Addresses where James L. Leenstra is enrolled with Medicare (CMS data updated October 2, 2026).
- 200 1st St SWRochester, MN 55905 (507) 284‑2511
- 700 W Ave SLa Crosse, WI 54601 (608) 785‑0940
- 800 W Ave SLa Crosse, WI 54601 (608) 785‑0940
Group practices
Medicare enrollment lists James L. Leenstra as a member of this group (CMS data updated October 2, 2026).
- Mayo Clinic4,956 clinicians in the group
Specialties
- Radiation Oncologyprimary
- Internal Medicinealso
Other radiation oncologists in Rochester
Clinicians with the same Medicare primary specialty in Rochester, MN — not a recommendation.
Other clinicians in Mayo Clinic
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Oklahoma College Of Medicine |
| Graduation year | 2002 (24 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1174593982 |
| 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 October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- 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