Doctor profile · Federal record

Dr. Jonathan Nass, M.D.

Gastroenterology Physician (CMS: Gastroenterology) · Internal Medicine Physician · Gastroenterology Physician · South Weymouth, MA

  • NPI 1558587998
  • Accepts Medicare
  • 21 yrs in practice
  • Licensed in 3 states
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
1085 Main St
South Weymouth, MA 021901547
(781) 331-2922
fax (781) 335-5702

Credentials & registration

NPPES · NUCC
NPI registered
April 2007 — 19 yrs on file
Profile last updated
December 18, 2019
Year of graduation
2005 — 21 yrs since
Specialty taxonomy
207RG0100X — NUCC code
State licenses (3)
Massachusetts #252551 · Rhode Island #LP00455 · Louisiana #MD.202069
Medicaid (2)
LA #1106887 · MS #05750222

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1558587998. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
817
Distinct HCPCS
10
Medicare allowed
$106,216
HCPCS Description Services Patients Avg allowed
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 161 91 $84
99222 Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 124 118 $138
45385 Removal of polyps or growths of large bowel using an endoscope with mechanical snare 98 93 $265
45380 Biopsy of large bowel using a flexible endoscope 87 87 $116
43239 Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 80 78 $114
99213 Established patient office or other outpatient visit, 20-29 minutes 40 35 $95
99214 Established patient office or other outpatient visit, 30-39 minutes 36 30 $136
99204 New patient office or other outpatient visit, 45-59 minutes 32 32 $170
43235 Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope 30 30 $130
45378 Diagnostic exam of large bowel using a flexible endoscope 23 23 $178

In context: peer comparison

Among 1 peers in this city , average services per provider: 51. This provider delivers 16× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
146
Patients
27
Total drug cost
$29,367
Drug Type Claims Patients Total cost
Pantoprazole Sodium Generic 65 27 $1,355
Linzess (Linaclotide) Brand 29 0 $18,180
Omeprazole Generic 19 0 $454
Adefovir Dipivoxil Generic 11 0 $8,128
Prednisone Generic 11 0 $112
Scopolamine Generic 11 0 $1,137

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Jonathan Nass's medical specialty?
Dr. Jonathan Nass practices Gastroenterology Physician in South Weymouth, MA.
Where does Dr. Jonathan Nass practice?
Dr. Jonathan Nass practices at 1085 Main St, South Weymouth, MA 021901547. Office phone: 7813312922.
What is Dr. Jonathan Nass's NPI?
Dr. Jonathan Nass's National Provider Identifier (NPI) is 1558587998, issued by NPPES.
Does Dr. Jonathan Nass accept Medicare assignment?
Yes. Dr. Jonathan Nass accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Jonathan Nass commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Initial hospital care with straightforward or low-level medical decision making (HCPCS 99222); Removal of polyps or growths of large bowel using an endoscope with mechanical snare (HCPCS 45385). Source: CMS Medicare Physician & Other Practitioners file.