DR. THOMAS E GREELY M.D.
NPI 1851336820
Family Medicine in Concord, CA
About Dr. Thomas E Greely M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. THOMAS E GREELY M.D. (NPI 1851336820) is an individual family medicine provider in Concord, California, licensed in California (G74271) and active in the NPI registry since June 2006. He is enrolled in Medicare PECOS and is a graduate of Ohio State University College Of Medicine (1989).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 4
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. Thomas E Greely M.d. 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
3Medicare enrollment records show Thomas Greely reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Walnut Creek, CA 94597
- Reassigned Medicare billing, California enrollment
- 650 clinicians in this Medicare group
Walnut Creek, CA 94598
- Reassigned Medicare billing, California enrollment
- 810 clinicians in this Medicare group
Chester, CA 96020
- Reassigned Medicare billing, California enrollment
- 38 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
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 94520 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.
CONCORD, CA 94520
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 Thomas Greely's NPI number?
The NPI number for Thomas Greely is 1851336820. It was assigned to this individual provider in the NPPES registry on June 16, 2006.
Where is Thomas Greely located?
Thomas Greely practices at 2700 Grant St Suite 200, Concord, CA 94520. The listed phone number is (925) 677-0500.
What is Thomas Greely's specialty?
The primary specialty registered for this NPI is Family Medicine with taxonomy code 207Q00000X.
Is Thomas Greely enrolled in Medicare?
Yes. Thomas Greely 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 Thomas Greely's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Thomas Greely reassigns Medicare benefits to 3 organizations: John Muir Physician Network (Walnut Creek, CA), John Muir Trauma Physicians Billing Service (Walnut Creek, CA) and Seneca Healthcare District (Chester, 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 Thomas Greely'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 Thomas Greely was last updated on March 25, 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. Thomas E Greely, M.D. · NPI 1851336820
Family Medicine physician in Concord, California. Individual provider, active in the CMS NPPES registry since June 16, 2006.
## Identity
- **NPI:** 1851336820 (Entity type: Individual)
- **Enumerated:** June 16, 2006
- **Primary specialty:** Family Medicine · taxonomy 207Q00000X
- **State license:** G74271 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 2700 GRANT ST, SUITE 200, Concord, CA 94520-2266
- **Phone:** (925) 677-0500 · **Fax:** (925) 677-0519
## 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:** 3 organizations under Medicare reassignment (form CMS-855R): John Muir Physician Network (NPI 1841407665, Walnut Creek, CA); John Muir Trauma Physicians Billing Service (NPI 1962551861, Walnut Creek, CA); Seneca Healthcare District (NPI 1326234022, Chester, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Ohio State University College Of Medicine, class of 1989
## Record status
- **NPPES last updated:** March 25, 2014
- **Other identifiers:** Medicare UPIN F42498 (CA); Medicare PIN 080132470 (CA); Medicare PIN 00G742711 (CA); and 1 more
---
Source: [NPI Profile](https://npiprofile.com/npi/1851336820) · Data from the CMS NPPES public registry.