Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Chester L Day, MD
Psychiatry Physician in Fairfax, VA · enumerated 2006.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1336224716
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Registry record
Entity type Individual (Type 1)
Name Chester L Day
Credential MD
Sex Male
Practice address 8221 Willow Oaks Corporate Dr Ste 4-420, Fairfax, VA, 22031
Phone (703) 289-7560
Fax (703) 204-9001
Enumeration date Oct 26, 2006
Last updated in NPPES Apr 5, 2022
Taxonomy & licenses
2084P0800X Psychiatry Physician Allopathic & Osteopathic Physicians · License 0415631 (KS) Secondary
2084P0800X Psychiatry Physician Allopathic & Osteopathic Physicians · License 0101257280 (VA) Primary
MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure.
About the MD credential
Other identifiers
| Identifier | Type | State | Issuer |
|---|---|---|---|
| 100139940C | Medicaid | KS | - |
| 106662 | Other | KS | BCBS |
What is an NPI number?
A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.
Frequently asked questions
What specialty is Chester Day?
Chester Day is registered in NPPES with the primary taxonomy of Psychiatry Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
Is this the official NPI registry?
No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.
Other providers at this practice address
Browse all → Afia Hussain Child & Adolescent Psychiatry Physician · Fairfax, VA NPI 1770674681 Nathan Pilgrim Psychiatry Physician · Fairfax, VA NPI 1255566105 Amal Sharifi Psychiatry Physician · Fairfax, VA NPI 1386937688 Kory Bradley Clinical Social Worker · Fairfax, VA NPI 1518243682 Khin Myint Psychiatry Physician · Fairfax, VA NPI 1649542200 Binu Abraham Clinical Social Worker · Fairfax, VA NPI 1457625527 Riddhi Kothari Psychiatry Physician · Fairfax, VA NPI 1629310701 Darlene Mack Clinical Social Worker · Fairfax, VA NPI 1821408253
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2022-04-05.