OSCAR CHEN MD, MS
NPI 1598329989
Ophthalmology in Lexington, MA
About Oscar Chen Md, Ms NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
OSCAR CHEN MD, MS (NPI 1598329989) is an individual ophthalmology provider in Lexington, Massachusetts, licensed in Massachusetts (1025773) and active in the NPI registry since May 2019. He is enrolled in Medicare PECOS and is a graduate of Rush Medical College Of Rush University (2021).
NPPES Registry Identity
Specialties & Licenses
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)
Oscar Chen Md, Ms is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
3Medicare enrollment records show Oscar Chen reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Lexington, MA 02421
- Reassigned Medicare billing, Massachusetts enrollment
- 37 clinicians in this Medicare group
Lexington, MA 02421
- Reassigned Medicare billing, Massachusetts enrollment
- 39 clinicians in this Medicare group
Orange, CA 92868
- Reassigned Medicare billing, California enrollment
- 113 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 02421 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.
LEXINGTON, MA 02421
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 Oscar Chen's NPI number?
The NPI number for Oscar Chen is 1598329989. It was assigned to this individual provider in the NPPES registry on May 1, 2019.
Where is Oscar Chen located?
Oscar Chen practices at 21 Worthen Rd, Lexington, MA 02421. The listed phone number is (781) 876-2020.
What is Oscar Chen's specialty?
The primary specialty registered for this NPI is Ophthalmology with taxonomy code 207W00000X.
Is Oscar Chen enrolled in Medicare?
Yes. Oscar Chen is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Oscar Chen's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Oscar Chen reassigns Medicare benefits to 3 organizations: Lexington Eye Associates - Bid (Lexington, MA), Lexington Eye Associates, Inc (Lexington, MA) and Regents Of The University Of California (Orange, CA). 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 Oscar Chen's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Oscar Chen accept?
Health plans from Anthem Blue Cross and Blue Sheld, Anthem Blue Cross and Blue Shield, Blue Cross and Blue Shield of Montana, Blue Cross and Blue Shield of Oklahoma and Blue Cross and Blue Shield of Texas and 1 other insurer list Oscar Chen 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 Oscar Chen was last updated on October 23, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 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.
# Oscar Chen, MD, MS · NPI 1598329989
Ophthalmology physician in Lexington, Massachusetts. Individual provider, active in the CMS NPPES registry since May 1, 2019.
## Identity
- **NPI:** 1598329989 (Entity type: Individual)
- **Enumerated:** May 1, 2019
- **Primary specialty:** Ophthalmology · taxonomy 207W00000X
- **State license:** 1025773 (Massachusetts)
- **Sole proprietor:** No
## Practice location
- **Address:** 21 WORTHEN RD, Lexington, MA 02421-4835
- **Phone:** (781) 876-2020
## 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): Lexington Eye Associates - Bid (NPI 1801204714, Lexington, MA); Lexington Eye Associates, Inc (NPI 1467502757, Lexington, MA); Regents Of The University Of California (NPI 1871541953, Orange, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Rush Medical College Of Rush University, class of 2021
## Record status
- **NPPES last updated:** October 23, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1598329989) · Data from the CMS NPPES public registry.