Office listed in NPPES
330 Mount Auburn St, Cambridge, MA 02138
(617) 499-5112
Confirm this address and number with the practice. Registry information may be outdated.
Physician directory profile
Steven I Master, MD
Cambridge, MA
Public records and practice information are labeled by source.
Accepts Medicare assignmentClaimed by a verified representative
Patient reviews are moderated.
Record details
- NPI
- 1255564837
- Registry updated
- 09/03/2014
- Imported
- 2026-11-03
- Registry specialty labels (English)
- Internal Medicine
Before arranging a visit
Confirm current services, ages treated, insurance, location, hospital affiliations and appointment availability directly with the practice. An active NPI does not verify current licensure, certification or practice status.
A registry specialty label does not establish that a clinician currently provides the particular care you need.
Background and affiliations
- Gender
- Male
- Medical school
- New York Medical College · graduated 2008
- Practice group
- Harvard Medical Faculty Phys at Beth Israel Deaconess Med Ctr · 1740 clinicians
- Offers telehealth
- No
- Accepts Medicare assignment
- Yes
Practice locations reported to Medicare
- 330 Brookline Ave, Boston, MA 02215 · (617) 754-8612
- 330 Brookline Ave, Boston, MA 02215
- 330 Mount Auburn St, Cambridge, MA 02138 · (781) 983-9088
Affiliated hospitals
- Mount Auburn Hospital · Cambridge, MA · CMS rating 4/5
Source: CMS Doctors and Clinicians and Hospital General Information. An affiliation does not confirm current privileges or the services offered there.
Industry payments
No 2025 general payments from drug or device companies were reported for Steven I Master. Research funding is excluded. These payments are public under the Sunshine Act, and a payment does not by itself mean a conflict of interest. CMS Open Payments
Insurance
- Medicare: accepts Medicare assignment (CMS).
- Other plans (for example Blue Cross Blue Shield of Massachusetts, Harvard Pilgrim Health Care, Tufts Health Plan) haven't been reported by this office yet. Call to confirm before booking.
Documented Medicare service activity
Reporting year: 2024. These are billed services or units in Original Medicare Part B, not total career experience, all patients, surgical case counts or a quality rating.
Scroll the table sideways to see every column.
| HCPCS | Billed services / units | Beneficiaries in this row | Service description (English) | Billing setting |
|---|---|---|---|---|
| 99222 | 36 | 36 | Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes | Facility |
| 99223 | 44 | 44 | Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | Facility |
| 99231 | 72 | 11 | Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes | Facility |
| 99232 | 313 | 167 | Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | Facility |
| 99233 | 324 | 179 | Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | Facility |
| 99238 | 48 | 48 | Hospital discharge day management, 30 minutes or less | Facility |
| 99239 | 138 | 136 | Hospital discharge day management, more than 30 minutes | Facility |
How to interpret these counts
CMS suppresses provider/service rows involving fewer than 11 beneficiaries. Services may repeat for one person, and beneficiaries cannot be added across rows. Facility/non-facility describes billing and does not establish a current hospital affiliation. These counts do not report case complexity, clinical outcomes or whether a treatment is appropriate for you.
Exact CMS source rows for this NPI · Checked 2026-11-03
Common questions
Where is Steven I Master's office?
The NPPES registry lists 330 Mount Auburn St, Cambridge, MA 02138. Confirm the location before your visit; registry addresses can be out of date. The registry entry was last updated in 2014; Medicare’s current enrollment lists 330 Mount Auburn St, Cambridge, MA 02138.
What phone number is listed for Steven I Master?
The registry lists (617) 499-5112. Practices sometimes change numbers; check the practice website if the call does not connect. Medicare lists (781) 983-9088 for this physician’s office.
What is Steven I Master's specialty?
The registry lists Internal medicine. A registry specialty is self-reported and does not confirm board certification or the services offered today.
Does Steven I Master bill Medicare?
CMS data shows publicly disclosed Original Medicare Part B services billed in 2024 (see above). That does not confirm the practice is accepting new Medicare patients; ask the office.
What is Steven I Master's NPI number?
NPI 1255564837, a public identifier from the national registry. It does not by itself confirm a current license.
Which hospitals is Steven I Master affiliated with?
Medicare records list Mount Auburn Hospital (Cambridge, MA). An affiliation does not confirm current privileges.
Does Steven I Master offer telehealth?
CMS records do not indicate telehealth services. Ask the office which visits can be done remotely.
Patient reviews
Reviews are moderated before publication, and negative reviews are published on the same terms as positive ones. Ratings describe reported patient experience, not clinical quality.
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