Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Dr. Donald James McMahon, DO

Individual provider Student in an Organized Health Care Education/Training Program · NPI 1285824839

Dr. Donald James McMahon, DO practises Gastroenterology in Turnersville, New Jersey. Graduated from Lake Erie College of Osteopathic Medicine, Erie in 2004, 22 years ago. Practices with Cooper Care Alliance, PC, a 118-clinician group and accepts Medicare assignment. Licensed in New Jersey.

Years since qualifying
22
Trained at
Lake Erie College of Osteopathic Medicine, Erie
Licensed in
NJ
In the registry since
2007
Specialties on file
2
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

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Practice location Address checks out

Student / training record This NPI belongs to someone enrolled in a health care training programme. It carries no licence and no practice of its own, so no address or phone number is published for it.

Turnersville, NJ

No coordinates on file. Search this address in Google Maps

Specialties & licences

Gastroenterology Physician (primary) Taxonomy 207RG0100X · Licence 25MB0862200 (NJ)
Student in an Organized Health Care Education/Training Program Taxonomy 390200000X

Record details

NPI number1285824839
Entity typeIndividual (Type 1)
GenderMale
Credentials DO
Sole proprietorNo
NPI enumeratedJuly 30, 2007
Last updated in NPPESJanuary 19, 2017

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyGASTROENTEROLOGY
Also practisesINTERNAL MEDICINE
Medical schoolLAKE ERIE COLLEGE OF OSTEOPATHIC MEDICINE, ERIE
Graduated 2004 (22 years in practice)
Group practice Cooper Care Alliance, Pc — 118 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Colonoscopy 44 times · 61st percentile
Upper gastrointestinal (GI) endoscopy for acid reflux 23 times · 52nd percentile

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients208
Services billed 303 a service is one billed item, such as a visit, a test or a procedure
Average patient age71

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Cooper Care Alliance, PC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 118 clinicians in the practice; 12 are shown here.

Other providers in Turnersville