DR. REX NEAL SMITH MD PHD
NPI 1801870910
Pathology - Immunopathology in Boston, MA
About Dr. Rex Neal Smith Md Phd NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. REX NEAL SMITH MD PHD (NPI 1801870910) is an individual immunopathology provider in Boston, Massachusetts, licensed in Massachusetts (150072) and active in the NPI registry since December 2005. He is enrolled in Medicare PECOS, is affiliated with Massachusetts General Hospital, and is a graduate of Clvlnd Clinic Lerner College Of Med Of Case Wstn Rsv University (1992).
NPPES Registry Identity
Specialties & Licenses 2
Other Identifiers 3
Accepted 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
Dr. Rex Neal Smith Md Phd 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.
Medicare Billing Reassignments
4Medicare enrollment records show Rex Smith reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Boston, MA 02114
- Reassigned Medicare billing, Massachusetts enrollment
- 6,360 clinicians in this Medicare group
Boston, MA 02114
- Reassigned Medicare billing, Massachusetts enrollment
- 6,234 clinicians in this Medicare group
Boston, MA 02115
- Reassigned Medicare billing, Massachusetts enrollment
- 4,574 clinicians in this Medicare group
Medford, MA 02155
- Reassigned Medicare billing, Massachusetts enrollment
- 258 clinicians in this Medicare group
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 13
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.
Hospital Affiliations CMS Care Compare 2
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Massachusetts General Hospital
Acute Care Hospitals · Boston, MABrigham And Women's Hospital
Acute Care Hospitals · Boston, MAPhysician 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.
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.
BOSTON, MA 02114
BOSTON, MA 02114
BOSTON, MA 02114
BOSTON, MA 02114
BOSTON, MA 02114
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 Rex Smith's NPI number?
The NPI number for Rex Smith is 1801870910. It was assigned to this individual provider in the NPPES registry on December 1, 2005.
Where is Rex Smith located?
Rex Smith practices at 55 Fruit Street Wrn 2 Pathology Associates, Boston, MA 02114. The listed phone number is (617) 726-1835.
What is Rex Smith's specialty?
The primary specialty registered for this NPI is Pathology, specializing in Immunopathology, with taxonomy code 207ZI0100X.
Is Rex Smith enrolled in Medicare?
Yes. Rex Smith 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 Rex Smith's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Rex Smith reassigns Medicare benefits to 4 organizations: Massachusetts General Physicians Organization Inc (Boston, MA), The General Hospital Corporation (Boston, MA), Brigham & Womens Physicians Organization Inc (Boston, MA) and Mass General Brigham Community Physicians Inc (Medford, 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 Rex Smith's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Rex Smith accept?
Health plans from Taro Health list Rex Smith 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 Rex Smith affiliated with any hospitals?
According to CMS data, Rex Smith is affiliated with Massachusetts General Hospital and Brigham And Women's Hospital.
When was this NPI record last updated?
The NPPES record for Rex Smith 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 3 months 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.
# Dr. Rex Neal Smith, MD PHD · NPI 1801870910
Immunopathology physician in Boston, Massachusetts. Individual provider, active in the CMS NPPES registry since December 1, 2005.
## Identity
- **NPI:** 1801870910 (Entity type: Individual)
- **Enumerated:** December 1, 2005
- **Primary specialty:** Pathology - Immunopathology · taxonomy 207ZI0100X
- **State license:** 150072 (Massachusetts)
- **Sole proprietor:** No
## Practice location
- **Address:** 55 FRUIT STREET, WRN 2 PATHOLOGY ASSOCIATES, Boston, MA 02114-2696
- **Phone:** (617) 726-1835 · **Fax:** (617) 726-2365
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 4 organizations under Medicare reassignment (form CMS-855R): Massachusetts General Physicians Organization Inc (NPI 1801874573, Boston, MA); The General Hospital Corporation (NPI 1023049236, Boston, MA); Brigham & Womens Physicians Organization Inc (NPI 1033535497, Boston, MA); Mass General Brigham Community Physicians Inc (NPI 1548638265, Medford, MA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Clvlnd Clinic Lerner College Of Med Of Case Wstn Rsv University, class of 1992
## Record status
- **NPPES last updated:** July 13, 2026
- **Other identifiers:** Medicaid 3156630 (MA); Other J16831 (MA); Other 150072 (MA)
---
Source: [NPI Profile](https://npiprofile.com/npi/1801870910) · Data from the CMS NPPES public registry.