Katherine A. Siamas, MD

Medicare activity in 2024

Official CMS public-use data for Katherine A. Siamas, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Most frequent services

1. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)368 services
2. Destruction of precancer skin growth, 2-14 growths (17003)252 services
3. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)251 services
4. Destruction of precancer skin growth, 1 growth (17000)168 services
5. Biopsy of related skin growth, first growth (11102)159 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

• High cholesterol75%
• High blood pressure68%
• Arthritis51%
• Ischemic heart disease27%
• Osteoporosis27%
• Diabetes26%

Hospitals where Katherine A. Siamas works

Medicare's Facility Affiliation Data lists Katherine A. Siamas at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

• Suny/Stony Brook University HospitalStony Brook, NY · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 330393

Practice locations

Addresses where Katherine A. Siamas is enrolled with Medicare (CMS data updated October 2, 2026).

• 1320 Stony Brook Rd, Suite 200Stony Brook, NY 11790 (631) 444‑4200

Group practices

Medicare enrollment lists Katherine A. Siamas as a member of this group (CMS data updated October 2, 2026).

• Stony Brook Dermatology Associates, University Faculty Practice Corpor11 clinicians in the group

Specialties

• Dermatologyprimary

Find other Dermatology doctors in New York →

Other dermatologists in Stony Brook

Clinicians with the same Medicare primary specialty in Stony Brook, NY — not a recommendation.

• Rachel N. Manci, MD
• Neal R. Shah
• Daniel F. Lozeau, MD
• Marcia G. Tonnesen, MD
• Elyse S. Rafal, MD
• Catherine A. Tawfik, DO
• Joann N. Salvemini, MD
• Jeremy M. Hugh, MD

All dermatologists in Stony Brook →

Other clinicians in Stony Brook Dermatology Associates, University Faculty Practice Corpor

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

• Neal R. Shah
• Tara L. Kaufmann, MD
• Evan C. Jones, MD
• Jeremy M. Hugh, MD
• Adrienne M. Haughton, MD
• Jordan B. Slutsky, MD

Clinician information

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
6. Medicare Care Compare — official Medicare tool to look up clinicians