GRACE K. MAHOWALD MD, PHD
NPI 1659665685
Pathology - Clinical Pathology in Boston, MA
About Grace K. Mahowald Md, Phd NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
GRACE K. MAHOWALD MD, PHD (NPI 1659665685) is an individual clinical pathology provider in Boston, Massachusetts, licensed in Massachusetts (L-247754) and active in the NPI registry since June 2011. She is enrolled in Medicare PECOS and maintains a secondary practice location in Boston.
NPPES Registry Identity
Specialties & Licenses
Secondary Practice Location 1
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Grace K. Mahowald Md, Phd is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
3Medicare enrollment records show Grace Mahowald reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Boston, MA 02115
- Reassigned Medicare billing, Massachusetts enrollment
- 4,574 clinicians in this Medicare group
Boston, MA 02114
- Reassigned Medicare billing, Massachusetts enrollment
- 6,234 clinicians in this Medicare group
Boston, MA 02114
- Reassigned Medicare billing, Massachusetts enrollment
- 6,360 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.
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.
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 Grace Mahowald's NPI number?
The NPI number for Grace Mahowald is 1659665685. It was assigned to this individual provider in the NPPES registry on June 7, 2011.
Where is Grace Mahowald located?
Grace Mahowald practices at Massachusetts General Hospital 55 Fruit Street, Boston, MA 02114. The listed phone number is (617) 726-2865.
What is Grace Mahowald's specialty?
The primary specialty registered for this NPI is Pathology, specializing in Clinical Pathology, with taxonomy code 207ZC0006X.
Is Grace Mahowald enrolled in Medicare?
Yes. Grace Mahowald is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Grace Mahowald's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Grace Mahowald reassigns Medicare benefits to 3 organizations: Brigham & Womens Physicians Organization Inc (Boston, MA), The General Hospital Corporation (Boston, MA) and Massachusetts General Physicians Organization Inc (Boston, 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 Grace Mahowald's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Grace Mahowald accept?
Health plans from Taro Health list Grace Mahowald 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.
When was this NPI record last updated?
The NPPES record for Grace Mahowald was last updated on July 21, 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.
# Grace K. Mahowald, MD, PHD · NPI 1659665685
Clinical Pathology physician in Boston, Massachusetts. Individual provider, active in the CMS NPPES registry since June 7, 2011.
## Identity
- **NPI:** 1659665685 (Entity type: Individual)
- **Enumerated:** June 7, 2011
- **Primary specialty:** Pathology - Clinical Pathology · taxonomy 207ZC0006X
- **State license:** L-247754 (Massachusetts)
- **Sole proprietor:** No
## Practice location
- **Address:** MASSACHUSETTS GENERAL HOSPITAL, 55 FRUIT STREET, Boston, MA 02114
- **Phone:** (617) 726-2865
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 3 organizations under Medicare reassignment (form CMS-855R): Brigham & Womens Physicians Organization Inc (NPI 1033535497, Boston, MA); The General Hospital Corporation (NPI 1023049236, Boston, MA); Massachusetts General Physicians Organization Inc (NPI 1801874573, Boston, MA) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** July 21, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1659665685) · Data from the CMS NPPES public registry.