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MAZEN NABIL NASRALLAH M.D
NPI 1609210004
Internal Medicine - Rheumatology in Boston, MA

Active since April 29, 2013PECOS EnrolledAccepts Medicare Assignment
55 FRUIT STREET, BULLFINCH, BOSTON, MA 02114(617) 726-3165 Get Directions Write a Review

NPPES record last updated: July 23, 2018. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Jul 23, 2018, Jul 17, 2018, Mar 17, 2018 and 1 more (4 updates tracked since 2018).

About Mazen Nabil Nasrallah M.d NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

MAZEN NABIL NASRALLAH M.D (NPI 1609210004) is an individual rheumatology provider in Boston, Massachusetts, licensed in Massachusetts (274389) and active in the NPI registry since April 2013. He is enrolled in Medicare PECOS, is affiliated with North Shore Medical Center -, and is a graduate of Other (2010).

NPPES Registry Identity

NPI1609210004
Entity TypeIndividualMale
Primary Taxonomy207RR0500X
Provider Legal NameMAZEN NABIL NASRALLAHCredential: M.D
Location Address55 FRUIT STREET, BULLFINCHBoston, MA 02114
Mailing Address55 Fruit Street, BullfinchBoston, MA 02114
Phone(617) 726-3165
Sole ProprietorYes
Medical School CMSOtherGraduated 2010
Enumeration DateApril 29, 2013
Last NPPES UpdateJuly 23, 20184 updates tracked since enumeration
✔ NPI 1609210004 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · RheumatologyAllopathic & Osteopathic Physicians
Taxonomy Code207RR0500X
Licenses✔ Licensed in MA · 274389✔ Licensed in MA · 266134
Definition
An internist who treats diseases of joints, muscle, bones and tendons. This specialist diagnoses and treats arthritis, back pain, muscle strains, common athletic injuries and collagen diseases.
55 FRUIT STREET, Boston, MA 02114
Open in Google Maps ↗

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Taro Health.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Mazen Nabil Nasrallah M.d is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID4082900139
PECOS Enrollment IDI20180813001342
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

4

Medicare enrollment records show Mazen Nasrallah reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Massachusetts General Physicians Organization Inc
Same address
Dermatology
55 FRUIT ST, BUL 2
Boston, MA 02114
  • Reassigned Medicare billing, Massachusetts enrollment
  • 6,360 clinicians in this Medicare group
NPI 1801874573 (617) 724-0287
The General Hospital Corporation
Same address
General Acute Care Hospital
55 FRUIT ST, BULFINCH 360
Boston, MA 02114
  • Reassigned Medicare billing, Massachusetts enrollment
  • 6,234 clinicians in this Medicare group
NPI 1023049236 (617) 726-2000
Steward Medical Group, Inc
6.0 mi
Specialist
9 GALEN ST
Watertown, MA 02472
  • Reassigned Medicare billing, Massachusetts enrollment
  • 1,103 clinicians in this Medicare group
NPI 1629398219 (615) 467-4474
Mass General Brigham Medical Group Northern Massachusetts Inc
13 mi
Emergency Medicine
81 HIGHLAND AVE
Salem, MA 01970
  • Reassigned Medicare billing, Massachusetts enrollment
  • 994 clinicians in this Medicare group
NPI 1588606123 (978) 354-4173

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 7

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
255 services147 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
170 services91 patients
New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more 99205
This is a first-time patient visit where a healthcare professional spends 60-74 minutes with you. It involves a comprehensive evaluation, including your medical history and current health condition. They'll also advise on preventive health measures and formulate a treatment plan if needed.
79 services79 patients
New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204
This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.
51 services51 patients
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213
This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.
34 services31 patients
Telephone medical discussion with physician, 21-30 minutes 99443
This service involves a 21-30 minute phone conversation with a physician. It's a chance for you to discuss your health concerns, symptoms or treatment plans. It's similar to an in-person consultation, but conducted over the phone for your convenience and safety.
25 services20 patients

Hospital Affiliations CMS Care Compare 3

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

North Shore Medical Center -

Acute Care Hospitals · Salem, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220035
Location81 Highland AvenueSalem, MA 01970 · Essex County
Emergency services Birthing friendly

Massachusetts General Hospital

Acute Care Hospitals · Boston, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220071
Location55 Fruit StreetBoston, MA 02114 · Suffolk County
Emergency services Birthing friendly

Wentworth-Douglass Hospital

Acute Care Hospitals · Dover, NH
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number300018
Location789 Central AveDover, NH 03820 · Strafford County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 02114 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$144.11 typical visit price
range $63.72 – $189.86
Typical copayment $36.02 (range $15.93 – $47.46)
Most-billed visit code 99204
Established Patient
$111.18 typical visit price
range $21.07 – $155.29
Typical copayment $27.79 (range $5.26 – $38.82)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

KUI TOH GERARD LEONG M.D.
Internal Medicine (Cardiovascular Disease)
55 FRUIT STREET, MASSACHUSETTS GENERAL HOSPITAL
BOSTON, MA 02114
Suffolk County (617) 726-8862
MS. JACQUELINE BANGO LICSW
Social Worker (Clinical)
55 FRUIT STREET, FOUNDERS BUILDING SUITE 880
BOSTON, MA 02114
Suffolk County (617) 643-8281
SARA ELIZABETH GROSSLEIN PA
Physician Assistant
55 FRUIT STREET, WHITE 1
BOSTON, MA 02114
Suffolk County (617) 724-4100
JEFFREY M ELLENBOGEN M.D.
Psychiatry & Neurology (Neurology)
55 FRUIT STREET, WANG 720 (NEUROLOGY)
BOSTON, MA 02114
Suffolk County (617) 724-7419
DR. NANCY LEE HARRIS MD
Pathology (Anatomic Pathology & Clinical Pathology)
55 FRUIT STREET, WRN 2 PATHOLOGY ASSOCIATES
BOSTON, MA 02114
Suffolk County (617) 726-5155
DR. STANLEY YANG SHAW MD PHD
Internal Medicine (Cardiovascular Disease)
55 FRUIT STREET, YAW 5 CARDIAC UNIT ASSOCIATES
BOSTON, MA 02114
Suffolk County (617) 724-6750
LEONARDO V RIELLA M.D., PHD
Internal Medicine
55 FRUIT STREET, WHITE 5
BOSTON, MA 02114
Suffolk County (617) 726-5050
SUSAN MAHER CRNA
Nurse Anesthetist, Certified Registered
55 FRUIT STREET, CLN 309 MGH ANESTHESIA ASSOCIATES
BOSTON, MA 02114
Suffolk County (617) 726-3030

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Mazen Nasrallah's NPI number?

The NPI number for Mazen Nasrallah is 1609210004. It was assigned to this individual provider in the NPPES registry on April 29, 2013.

Where is Mazen Nasrallah located?

Mazen Nasrallah practices at 55 Fruit Street Bullfinch, Boston, MA 02114. The listed phone number is (617) 726-3165.

What is Mazen Nasrallah's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Rheumatology, with taxonomy code 207RR0500X.

Is Mazen Nasrallah enrolled in Medicare?

Yes. Mazen Nasrallah is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organizations bill Medicare for Mazen Nasrallah's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Mazen Nasrallah reassigns Medicare benefits to 4 organizations: Massachusetts General Physicians Organization Inc (Boston, MA), The General Hospital Corporation (Boston, MA), Steward Medical Group, Inc (Watertown, MA) and Mass General Brigham Medical Group Northern Massachusetts Inc (Salem, MA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Mazen Nasrallah's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Mazen Nasrallah accept?

Health plans from Taro Health list Mazen Nasrallah as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Mazen Nasrallah affiliated with any hospitals?

According to CMS data, Mazen Nasrallah is affiliated with North Shore Medical Center -, Massachusetts General Hospital and Wentworth-Douglass Hospital.

When was this NPI record last updated?

The NPPES record for Mazen Nasrallah was last updated on July 23, 2018. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 8 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.