DR. SEAN GRAMMY D.O.
NPI 1982832127
Emergency Medicine in Antioch, CA
About Dr. Sean Grammy D.o. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. SEAN GRAMMY D.O. (NPI 1982832127) is an individual emergency medicine provider in Antioch, California, licensed in California (20A13122) and active in the NPI registry since June 2009. He is enrolled in Medicare PECOS.
NPPES Registry Identity
Specialties & Licenses 2
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Dr. Sean Grammy D.o. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
2Medicare enrollment records show Sean Grammy reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Antioch, CA 94509
- Reassigned Medicare billing, California enrollment
- 2,323 clinicians in this Medicare group
Walnut Creek, CA 94597
- Reassigned Medicare billing, California enrollment
- 650 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 4
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.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 94509 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
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.
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 Sean Grammy's NPI number?
The NPI number for Sean Grammy is 1982832127. It was assigned to this individual provider in the NPPES registry on June 25, 2009.
Where is Sean Grammy located?
Sean Grammy practices at 3901 Lone Tree Way, Antioch, CA 94509. The listed phone number is (925) 779-7200.
What is Sean Grammy's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Sean Grammy enrolled in Medicare?
Yes. Sean Grammy is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Sean Grammy's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Sean Grammy reassigns Medicare benefits to 2 organizations: Cep America - California (Antioch, CA) and John Muir Physician Network (Walnut Creek, 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 Sean Grammy's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Sean Grammy was last updated on July 28, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 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.
# Dr. Sean Grammy, D.O. · NPI 1982832127
Emergency Medicine physician in Antioch, California. Individual provider, active in the CMS NPPES registry since June 25, 2009.
## Identity
- **NPI:** 1982832127 (Entity type: Individual)
- **Enumerated:** June 25, 2009
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** 20A13122 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 3901 LONE TREE WAY, Antioch, CA 94509-6200
- **Phone:** (925) 779-7200
## 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:** 2 organizations under Medicare reassignment (form CMS-855R): Cep America - California (NPI 1912930421, Antioch, CA); John Muir Physician Network (NPI 1841407665, Walnut Creek, CA) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** July 28, 2014
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Source: [NPI Profile](https://npiprofile.com/npi/1982832127) · Data from the CMS NPPES public registry.