Physician Profile
Ioannis Mastoris, MD
Unclaimed ProfileAbout Dr. Mastoris
Based in Boston, MA, Ioannis Mastoris, MD is listed in the NPI registry under internal medicine. Ioannis is also listed as specializing in cardiovascular disease. Medicare claims data shows Ioannis provided 1,257 services to 665 patients. The services billed most often include established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more, routine electrocardiogram (ecg) using at least 12 leads with interpretation and report, and subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes.
Summarised automatically from public NPI registry and CMS Medicare data. Not written or reviewed by this provider. Claim this profile to replace it.
Education & Training
Specialty
Credentials & Licensing
License numbers are what the provider reported to NPPES when the NPI was issued or updated. NPPES does not verify licensure; confirm current standing with the state licensing board.
Medicare information
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
Contact Information
- (617) 643-7972
- Email not available
Practice Locations
55 FRUIT ST GRB 800
Boston, MA 02114
67 Corporate Dr Ste 200
Portsmouth, NH 03801
Conditions Commonly Evaluated or Treated
Within Internal Medicine generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Conditions
Most searched conditions
Cardiometabolic
Digestive and liver
Endocrine, blood, and bone
Infectious disease
Kidney and urinary
Respiratory
Blood & Circulation
Blood disorders
Brain & Nerves
Brain and nerves
Cardiac and vascular
Digestive
Heart & Circulation
Infections
Kidney & Bladder
Lungs & Breathing
Mental Health
Neurologic and behavioral
Pain
Rheumatologic and pain
Procedures & services
Most searched procedures
Preventive and evaluation
Screening and diagnostic testing
Bones & Joints
Brain and nerves
Cancer screening
Digestive
Exams & Consultations
Heart & Circulation
Heart health
Imaging referral
Immunizations
Lab tests
Lungs & Breathing
Metabolic & Weight
Minor procedures
Office procedures
Office Procedures
Pain management
Preventive & Routine Care
Screenings & Diagnostics
Sexual health
Procedures Most Often Billed to Medicare
1,257 services · 665 patients · 13 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report | Treatment | 93000 |
216 | More than most peers in Internal Medicine |
| Evaluation of lower heart chamber assist device | Treatment | 93750 |
44 | As often as other peers in Internal Medicine |
| Evaluation of lower heart chamber assist device | Treatment | 93750 |
29 | As often as other peers in Internal Medicine |
| Evaluation of implantable heart and blood vessel monitoring system, remote up to 30 days | Treatment | 93297 |
19 | Less often than most peers in Internal Medicine |
| Insertion of tube in right heart chambers for measurement | Treatment | 93451 |
17 | Less often than most peers in Internal Medicine |
| Biopsy of heart muscle | Treatment | 93505 |
15 | Less often than most peers in Internal Medicine |
| Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more | Office visit | 99215 |
286 | More than most peers in Internal Medicine |
| Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | Office visit | 99233 |
213 | More often than most peers in Internal Medicine |
| Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient' | Billing code | G2211 |
164 | As often as other peers in Internal Medicine |
| Critical care, first 30-74 minutes | Office visit | 99291 |
128 | More often than most peers in Internal Medicine |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Other internists at this location 1
Same specialty, same street address — most likely the same department or group.
Related specialists at this location 8
Clinically related specialties at the same address — the people this provider most likely works alongside.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
More connections — 31 related providers in 4 groups
Other internists in Boston 7
Same specialty, same city.
Trained at Other 8
Other providers in the same specialty who trained at the same institution.
Class of 2011 at Other 8
Providers who graduated from the same medical school in the same year.
Also performs Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 8
Providers in MA who bill this service to Medicare most often.
Common questions
What kind of doctor is Dr. Mastoris?
Dr. Mastoris is an internist in Boston, MA. That is the designation recorded for this NPI in the federal registry, where it is listed as “Internal Medicine”.
NPI registry
What is Dr. Mastoris's address?
Dr. Mastoris is listed at 55 Fruit St Grb 800, Boston, MA 02114. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
How can I make an appointment with Dr. Mastoris?
The number on file is (617) 643-7972. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
What is the NPI for Dr. Mastoris?
Dr. Mastoris's National Provider Identifier is 1124403209. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
Where did Dr. Mastoris train?
Dr. Mastoris attended Other, graduating in 2011. This comes from the CMS National Downloadable File.
CMS public data
How much experience does Dr. Mastoris have?
Dr. Mastoris has 15 years experience. Calculated from a graduation year of 2011, reported in the CMS National Downloadable File.
CMS public data
What procedures does Dr. Mastoris perform?
According to Medicare billing data, Dr. Mastoris provides treatments such as routine electrocardiogram using at least 12 leads with interpretation and report and evaluation of lower heart chamber assist device, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Is Dr. Mastoris's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Mastoris. If this is you, claiming it is free.
Guide.md
Provider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.