David K. Hahn, MD

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.

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.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

• White Plains Hospital Center Hospital · White Plains, NY
• Midstate Medical Center Hospital · Meriden, CT
• Norwalk Hospital Hospital · Norwalk, CT
• The Hospital Of Central Connecticut Hospital · New Britain, CT

Colleagues at The Hospital of Central Connecticut at New Britain General and Bradley

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 392 clinicians in the practice; 12 are shown here.

• Dr. Olurotimi Olusegun Adekolu, MBCHB Internal Medicine Physician · New Haven, CT
• Mojisola Omotayo Araoye, MD Hematology & Oncology Physician · Farmington, CT
• Rozah Arran Physician Assistant · Worcester, MA
• Catherine Champagne Adult Health Nurse Practitioner · Monroe, CT
• Dr. Gregory Scott Heaphy, MD Emergency Medicine Physician · Portland, ME
• Dr. Ujwol Karmacharya, MD Internal Medicine Physician · New Britain, CT
• Dr. David Robert Lloyd, MD Internal Medicine Physician · New Britain, CT
• Dr. Ariel Ong, MD Student in an Organized Health Care Education/Training Program · New Britain, CT
• Gagan D. Singh, MD Hospitalist Physician · Hartford, CT
• Victoria Drumski Swider, PA-C Surgical Physician Assistant · New Britain, CT
• Nelson Ben Thomas III Internal Medicine Physician · New Haven, CT
• Zhenghao Zhang, MDPHD Internal Medicine Physician · Brockton, MA

Other providers in Greenwich

• Lori Jensen, MD

  Individual Neurology Physician · NPI 1619934130

  15 Valley Dr Ste 201, Greenwich, CT 06831-5205 · (203) 863-4490

• Mason Street Industries LLC

  Organization Neurology Physician · NPI 1215805536

  115 Mason St Ste 1, Greenwich, CT 06830-6630 · (718) 514-0224

• Matthew Wells McConnell, MD

  Individual Neurology Physician · NPI 1699018044

  49 Lake Ave Lowr LEVEL3, Greenwich, CT 06830-4501 · (203) 900-4226

• Andrew Michalak, MD

  Individual Neurology Physician · NPI 1720440985

  5 Perryridge Rd, Greenwich, CT 06830-4608 · (203) 863-3409