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

Mark E Mass, MD

Individual provider Emergency Medical Services (Emergency Medicine) Physician · NPI 1841276847

Mark E Mass, MD practises Emergency Medicine in Lake Forest, Illinois. Graduated from University of Illinois College of Med (CHI/PEOR/ROCK/Chm-Urb) in 1988, 38 years ago. Practices with Mass Medical SC, a 5-clinician group and accepts Medicare assignment. Licensed in Illinois.

Years since qualifying
38
Trained at
University of Illinois College of Med (CHI/PEOR/ROCK/Chm-Urb)
Licensed in
IL
In the registry since
2005
Specialties on file
5
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

1025 W Everett Rd Ste 101
Lake Forest, IL 60045-2697 Not confirmed with CMS for 12 years — call before visiting
Phone: (847) 234-7950
Fax: (847) 234-7940
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Urgent Care Clinic/Center (primary) Taxonomy 261QU0200X · Licence 036-093222 (IL)
Emergency Medical Services (Emergency Medicine) Physician Taxonomy 207PE0004X · Licence 36093222 (IL)
Occupational Medicine Physician Taxonomy 2083X0100X · Licence 036-093222 (IL)
Emergency Medicine Physician Taxonomy 207P00000X · Licence 036-093222 (IL)
Occupational Medicine Clinic/Center Taxonomy 261QX0100X · Licence 036-093222 (IL)

Record details

NPI number1841276847
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedDecember 21, 2005
Last updated in NPPESApril 23, 2014

Medicare enrollment

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

Medicare specialtyEMERGENCY MEDICINE
Medical schoolUNIVERSITY OF ILLINOIS COLLEGE OF MED (CHI/PEOR/ROCK/CHM-URB)
Graduated 1988 (38 years in practice)
Group practice Mass Medical Sc — 5 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.

Removal of nail tissue 1–10 times
Removal of skin lesions 1–10 times
Removal of tissue 1–10 times

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 patients581
Services billed 2,633 a service is one billed item, such as a visit, a test or a procedure
Average patient age77

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. Those with a page here are linked.

Colleagues at Mass Medical SC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 5 clinicians in the practice; 2 are shown here.

Other providers in Lake Forest