Physician Profile
John W. Mahan, MD is a healthcare provider in Great Falls, MT specializing in internal medicine. John trained at University of New Mexico School of Medicine, graduating in 1989. According to Medicare claims data, John cared for 492 Medicare patients across 1,053 services. The services billed most often include subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes, subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes, and initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes.
Summarised automatically from public NPI registry and CMS Medicare data. Not written or reviewed by this provider. Claim this profile to replace it.
License numbers are what the provider reported to NPPES when the NPI was issued or updated. NPPES does not verify licensure; confirm current standing with the state licensing board.
1101 26TH ST S
Great Falls, MT 59405
Within Internal Medicine generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Most searched conditions
Cardiometabolic
Digestive and liver
Endocrine, blood, and bone
Infectious disease
Kidney and urinary
Respiratory
Blood & Circulation
Blood disorders
Brain & Nerves
Brain and nerves
Cardiac and vascular
Digestive
Heart & Circulation
Infections
Kidney & Bladder
Lungs & Breathing
Mental Health
Neurologic and behavioral
Pain
Rheumatologic and pain
Most searched procedures
Preventive and evaluation
Screening and diagnostic testing
Bones & Joints
Brain and nerves
Cancer screening
Digestive
Exams & Consultations
Heart & Circulation
Heart health
Imaging referral
Immunizations
Lab tests
Lungs & Breathing
Metabolic & Weight
Minor procedures
Office procedures
Office Procedures
Pain management
Preventive & Routine Care
Screenings & Diagnostics
Sexual health
1,053 services · 492 patients · 4 distinct codes
| Procedure | Type | Code | Services |
|---|---|---|---|
| Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | Office visit | 99232 |
503 |
| Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | Office visit | 99233 |
267 |
| Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | Office visit | 99223 |
153 |
| Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes | Office visit | 99231 |
130 |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Dr. Mahan is an internal medicine in Great Falls, MT. That is the designation recorded for this NPI in the federal registry.
NPI registry
Dr. Mahan is listed at 1101 26Th St S, Great Falls, MT 59405. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
The number on file is (406) 731-8888. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
Dr. Mahan's National Provider Identifier is 1346241296. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
Dr. Mahan attended University of New Mexico School of Medicine, graduating in 1989. This comes from the CMS National Downloadable File.
CMS public data
Dr. Mahan has 37 years experience. Calculated from a graduation year of 1989, reported in the CMS National Downloadable File.
CMS public data
According to Medicare billing data, Dr. Mahan the Medicare record under this individual NPI shows mainly office visits and diagnostic testing. Hospital-based physicians usually have their procedural work billed by the facility rather than under their own number, so this is a floor on their practice, not a description of it. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Mahan. If this is you, claiming it is free.
Guide.md
Provider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.