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

Mark Leo Timmerman, MD

Individual provider Family Medicine Physician · NPI 1972525574

Mark Leo Timmerman, MD is registered under Family Practice in Merrimack, New Hampshire. Graduated from University of Iowa, Rj & L Carver College of Medicine in 1984, 42 years ago. Practices as a sole proprietor and accepts Medicare assignment. Licensed in New Hampshire.

Years since qualifying
42
Trained at
University of Iowa, Rj & L Carver College of Medicine
Licensed in
NH
In the registry since
2006
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

454 Daniel Webster Hwy
Merrimack, NH 03054-3699
Phone: (603) 424-8120
Fax: (603) 424-8140
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Family Medicine Physician (primary) Taxonomy 207Q00000X · Licence NH 7663 (NH)

Record details

NPI number1972525574
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedJuly 24, 2006
Last updated in NPPESMarch 7, 2023

Medicare enrollment

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

Medicare specialtyFAMILY PRACTICE
Medical schoolUNIVERSITY OF IOWA, RJ & L CARVER COLLEGE OF MEDICINE
Graduated 1984 (42 years in practice)
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations3 on file with Medicare

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 skin lesions 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 patients76
Services billed 281 a service is one billed item, such as a visit, a test or a procedure
Average patient age76

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.

Other providers in Merrimack