JOHN WEST DAY MD
NPI 1447291992
Psychiatry & Neurology - Neuromuscular Medicine in Stanford, CA
About John West Day Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
JOHN WEST DAY MD (NPI 1447291992) is an individual neuromuscular medicine provider in Stanford, California, licensed in California (G52734) and active in the NPI registry since June 2006. He is enrolled in Medicare PECOS, maintains a secondary practice location in Palo Alto, and is a graduate of University Of Minnesota Medical School (1977).
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
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
John West Day Md 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 John Day reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Stanford, CA 94305
- Reassigned Medicare billing, California enrollment
- 4,258 clinicians in this Medicare group
Palo Alto, CA 94304
- Reassigned Medicare billing, California enrollment
- 3,617 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.
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.
STANFORD, CA 94305
STANFORD, CA 94305
STANFORD, CA 94305
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 John Day's NPI number?
The NPI number for John Day is 1447291992. It was assigned to this individual provider in the NPPES registry on June 8, 2006.
Where is John Day located?
John Day practices at 300 Pasteur Dr, Stanford, CA 94305. The listed phone number is (650) 723-4000.
What is John Day's specialty?
The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Neuromuscular Medicine, with taxonomy code 2084N0008X.
Is John Day enrolled in Medicare?
Yes. John Day 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 John Day's services?
According to the CMS Revalidation Reassignment List (October 2026 release), John Day reassigns Medicare benefits to 2 organizations: Stanford Health Care (Stanford, CA) and Lpch Medical Group Div Of Lucile (Palo Alto, 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 John Day'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 John Day was last updated on November 9, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.
# John West Day, MD · NPI 1447291992
Neuromuscular Medicine physician in Stanford, California. Individual provider, active in the CMS NPPES registry since June 8, 2006.
## Identity
- **NPI:** 1447291992 (Entity type: Individual)
- **Enumerated:** June 8, 2006
- **Primary specialty:** Psychiatry & Neurology - Neuromuscular Medicine · taxonomy 2084N0008X
- **State license:** G52734 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 300 PASTEUR DR, Stanford, CA 94305-2200
- **Phone:** (650) 723-4000
## 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): Stanford Health Care (NPI 1437292927, Stanford, CA); Lpch Medical Group Div Of Lucile (NPI 1417907940, Palo Alto, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Minnesota Medical School, class of 1977
## Record status
- **NPPES last updated:** November 9, 2023
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Source: [NPI Profile](https://npiprofile.com/npi/1447291992) · Data from the CMS NPPES public registry.