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

Jon J Ernstoff, MD

Individual provider Gastroenterology Physician · NPI 1598789653

Jon J Ernstoff, MD practises Gastroenterology in Meriden, Connecticut. Qualified in 1978, 48 years ago. Practices with Baystate Medical Practices Inc, a 1,346-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in Connecticut and Massachusetts.

Years since qualifying
48
Licensed in
CT, MA
In the registry since
2006
Specialties on file
3
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

455 Lewis Ave Ste 106
Meriden, CT 06451-2121
Phone: (203) 886-0036
Fax: (203) 886-0072
Show map & directions

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

Additional practice locations (1)

  • 48 Sanderson St Fl 2, Greenfield, MA 01301-2778 — (413) 773-2655

Specialties & licences

Gastroenterology Physician (primary) Taxonomy 207RG0100X · Licence 025772 (CT)
Gastroenterology Physician Taxonomy 207RG0100X · Licence 1022596 (MA)
Internal Medicine Physician Taxonomy 207R00000X · Licence 025772 (CT)

Record details

NPI number1598789653
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 26, 2006
Last updated in NPPESApril 3, 2025
Certification dateApril 3, 2025

Medicare enrollment

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

Medicare specialtyGASTROENTEROLOGY
Medical schoolOTHER
Graduated 1978 (48 years in practice)
Group practice Baystate Medical Practices Inc — 1346 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 85 times · 76th percentile
Upper gastrointestinal (GI) endoscopy for acid reflux 62 times · 67th 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 patients32
Services billed 48 a service is one billed item, such as a visit, a test or a procedure
Average patient age75

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 Baystate Medical Practices Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 1346 clinicians in the practice; 12 are shown here.

Other providers in Meriden