Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

DR. ROBERT PAUL HASSERJIAN MD
NPI 1285625574
Pathology - Hematology in Boston, MA

Active since November 04, 2005PECOS Enrolled
55 FRUIT ST, WRN 225, BOSTON, MA 02114(617) 724-1445(617) 726-7474 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Jul 13, 2026, Sep 11, 2025 (2 updates tracked since 2025).

About Dr. Robert Paul Hasserjian Md NPPES

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

DR. ROBERT PAUL HASSERJIAN MD (NPI 1285625574) is an individual hematology provider in Boston, Massachusetts, licensed in Massachusetts (80560) and active in the NPI registry since November 2005. He is enrolled in Medicare PECOS, is affiliated with Cooley Dickinson Hospital Inc,the, and is a graduate of Harvard Medical School (1990).

NPPES Registry Identity

NPI1285625574
Entity TypeIndividualMale
Primary Taxonomy207ZH0000X
Provider Legal NameDR. ROBERT PAUL HASSERJIANCredential: MD
Location Address55 FRUIT ST, WRN 225Boston, MA 02114-2696
Mailing AddressPo Box 9142Charlestown, MA 02129-9142 · (617) 724-0287 · Fax (617) 726-2894
Fax(617) 726-7474
Sole ProprietorNo
Medical School CMSHarvard Medical SchoolGraduated 1990
Enumeration DateNovember 4, 2005
Last NPPES UpdateJuly 13, 20262 updates tracked since enumeration
NPI 1285625574 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

Primary SpecialtyPathology · HematologyAllopathic & Osteopathic Physicians
Taxonomy Code207ZH0000X
License Licensed in MA · 80560
Definition
A hematopathologist is expert in diseases that affect blood cells, blood clotting mechanisms, bone marrow and lymph nodes. This physician has the knowledge and technical skills essential for the laboratory diagnosis of anemias, leukemias, lymphomas, bleeding disorders and blood clotting disorders.
Also ListedPathology · Anatomic PathologyTaxonomy 207ZP0101X · License 80560 (MA)
55 FRUIT ST, Boston, MA 02114

Other Identifiers 3

Medicaid3139514MA
OtherJ31606MA · Bcbs Ma
Other751191MA · Tufts Health Plan

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

Enrolled in Medicare and accepts Medicare assignment

Dr. Robert Paul Hasserjian Md 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 ID9335127760
PECOS Enrollment IDI20040712000532
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.

Areas of Expertise CMS Part B claims 16

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.

Special stained specimen slides to examine tissue, each additional procedure 88341
Special stained specimen slides are used to analyze tissue in detail. In this process, extra procedures may be needed for a more thorough examination. These involve applying special stains to the tissue on slides, enhancing specific elements for closer study.
906 services170 patients
Special stained specimen slides to examine tissue including interpretation and report 88313
Special stained specimen slides are used to examine tissue samples. This involves applying special dyes to the tissue, which helps to highlight certain features under a microscope. The findings are then interpreted and a report is provided. This can aid in diagnosing various health conditions.
485 services195 patients
Pathology examination of tissue using a microscope, intermediate complexity 88305
A pathology examination of tissue with intermediate complexity involves studying a small sample of your body tissue under a microscope. This helps in identifying any abnormal cells or signs of disease. It's a detailed process requiring expert analysis to ensure accurate results.
354 services229 patients
Microscopic genetic analysis of tumor, manual 88360
Microscopic genetic analysis of a tumor involves examining your tumor's genes under a microscope. This helps identify specific genetic changes in the tumor cells. This information can aid in diagnosing, predicting disease progression, and determining the most effective treatment options.
259 services152 patients
Bone marrow, smear interpretation 85097
Bone marrow smear interpretation is a procedure where a small sample of your bone marrow is taken and examined under a microscope. This helps doctors identify any abnormal cells or signs of diseases such as anemia, leukemia, or infections. It's a crucial step in diagnosing various blood disorders.
234 services186 patients
Preparation of tissue for examination by removing any calcium present 88311
This procedure involves treating tissue samples to remove any calcium, which can interfere with the examination. The tissue is soaked in a special solution that safely dissolves the calcium, leaving the tissue intact for accurate analysis. This helps in making precise diagnoses.
230 services181 patients

Hospital Affiliations CMS Care Compare 4

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

Cooley Dickinson Hospital Inc,the

Acute Care Hospitals · Northampton, MA
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220015
Location30 Locust StreetNorthampton, MA 01060 · Hampshire 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

Massachusetts Eye And Ear Infirmary -

Acute Care Hospitals · Boston, MA
OwnershipVoluntary non-profit - Private
CMS Certification Number220075
Location243 Charles StreetBoston, MA 02114 · Suffolk County
Emergency services

Brigham And Women's Hospital

Acute Care Hospitals · Boston, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220110
Location75 Francis StreetBoston, MA 02115 · Suffolk 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.

Pathology (Anatomic Pathology)
55 FRUIT ST
BOSTON, MA 02114
Internal Medicine (Hematology & Oncology)
55 FRUIT ST
BOSTON, MA 02114
Anesthesiology
55 FRUIT ST, GRAY-BIGELOW 444
BOSTON, MA 02114
Physical Medicine & Rehabilitation
55 FRUIT ST
BOSTON, MA 02114
Internal Medicine (Infectious Disease)
55 FRUIT ST, DIVISION OF INFECTIOUS DISEASE, GRJ-504
BOSTON, MA 02114
Nurse Practitioner (Acute Care)
55 FRUIT ST, BIGALOW 852 F
BOSTON, MA 02114
Nurse Practitioner
55 FRUIT ST
BOSTON, MA 02114
Internal Medicine (Cardiovascular Disease)
55 FRUIT ST
BOSTON, MA 02114

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 Robert Hasserjian's NPI number?

The NPI number for Robert Hasserjian is 1285625574. It was assigned to this individual provider in the NPPES registry on November 4, 2005.

Where is Robert Hasserjian located?

Robert Hasserjian practices at 55 Fruit St Wrn 225, Boston, MA 02114. The listed phone number is (617) 724-1445.

What is Robert Hasserjian's specialty?

The primary specialty registered for this NPI is Pathology, specializing in Hematology, with taxonomy code 207ZH0000X.

Is Robert Hasserjian enrolled in Medicare?

Yes. Robert Hasserjian 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.

Is Robert Hasserjian affiliated with any hospitals?

According to CMS data, Robert Hasserjian is affiliated with Cooley Dickinson Hospital Inc,the, Massachusetts General Hospital, Massachusetts Eye And Ear Infirmary - and Brigham And Women's Hospital.

When was this NPI record last updated?

The NPPES record for Robert Hasserjian was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 24 days 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.