HELEN KEIZHEN LYO
NPI 1609336676
Internal Medicine in Boston, MA
About Helen Keizhen Lyo NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
HELEN KEIZHEN LYO (NPI 1609336676) is an individual internal medicine provider in Boston, Massachusetts, licensed in Massachusetts (291273) and active in the NPI registry since March 2019. She is enrolled in Medicare PECOS, is affiliated with John H Stroger Jr Hospital, and is a graduate of State University Of New York Downstate Medical Center (2019).
NPPES Registry Identity
Specialties & Licenses
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
Helen Keizhen Lyo 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
2Medicare enrollment records show Helen Lyo reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Waldorf, MD 20603
- Reassigned Medicare billing, District of Columbia and Virginia enrollments
- Also billed through NPI 1275097123 (Virginia)
- 2,618 clinicians in this Medicare group
Chicago, IL 60637
- Reassigned Medicare billing, Illinois enrollment
- 1,047 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.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
John H Stroger Jr Hospital
Acute Care Hospitals · Chicago, ILPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 02118 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 02118
BOSTON, MA 02118
BOSTON, MA 02118
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 Helen Lyo's NPI number?
The NPI number for Helen Lyo is 1609336676. It was assigned to this individual provider in the NPPES registry on March 25, 2019.
Where is Helen Lyo located?
Helen Lyo practices at 801 Massachusetts Ave Crosstown 2, Boston, MA 02118. The listed phone number is (617) 414-7399.
What is Helen Lyo's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Helen Lyo enrolled in Medicare?
Yes. Helen Lyo 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 Helen Lyo's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Helen Lyo reassigns Medicare benefits to 2 organizations: Inova Health Care Services (Waldorf, MD) and Cook County (Chicago, IL). 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 Helen Lyo's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is Helen Lyo affiliated with any hospitals?
According to CMS data, Helen Lyo is affiliated with John H Stroger Jr Hospital.
When was this NPI record last updated?
The NPPES record for Helen Lyo was last updated on May 17, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.
# Helen Keizhen Lyo · NPI 1609336676
Internal Medicine physician in Boston, Massachusetts. Individual provider, active in the CMS NPPES registry since March 25, 2019.
## Identity
- **NPI:** 1609336676 (Entity type: Individual)
- **Enumerated:** March 25, 2019
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** 291273 (Massachusetts)
- **Sole proprietor:** No
## Practice location
- **Address:** 801 MASSACHUSETTS AVE, CROSSTOWN 2, Boston, MA 02118-0211
- **Phone:** (617) 414-7399 · **Fax:** (617) 414-4676
## 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:** 2 organizations under Medicare reassignment (form CMS-855R): Inova Health Care Services (NPI 1851829550, Waldorf, MD); Cook County (NPI 1497874325, Chicago, IL) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** State University Of New York Downstate Medical Center, class of 2019
## Record status
- **NPPES last updated:** May 17, 2022
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Source: [NPI Profile](https://npiprofile.com/npi/1609336676) · Data from the CMS NPPES public registry.