NPIMap

Individual provider Active NPI

Joshua M Allen, MD

  • Medical Oncology Physician
  • Fairfax, VA
National Provider Identifier
1942628458
Registry record updated Apr 22, 2026
On this page

Key facts

NPPES NPI Registry
Primary specialty
Medical Oncology PhysicianTaxonomy code 207RX0202X
License
0101268640 Issued in VA
Practice address
3580 Joseph Siewick Dr Ste 403
Fairfax, VA 22033-1764
Phone
(703) 391-4395
Fax
(703) 391-4394
NPI assigned
Apr 1, 2014
Last updated
Apr 22, 2026By the provider in NPPES
Sex
Male
Sole proprietor
No

NPPES NPI Registry

Updated by the provider on Apr 22, 2026

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 3

Specialty (taxonomy)CodeLicenseStatePrimary
Internal Medicine Physician 207R00000X 0101268640 VA
Hematology (Internal Medicine) Physician 207RH0000X 0101268640 VA
Medical Oncology Physician 207RX0202X 0101268640 VA Primary

Addresses

Primary practice location

3580 Joseph Siewick Dr Ste 403
Fairfax, VA 22033-1764

Mailing address

PO Box 37174
Baltimore, MD 21297-3174
Phone (571) 423-5699

Other practice location 1

8081 Innovation Park Dr
Fairfax, VA 22031-4867
Phone (571) 472-4724

Medicare participation

Medicare enrollment files
Medicare fee-for-service enrollment
Enrolled in DC, VA2 enrollments
Eligible to order & refer
  • Part B services
  • Medical equipment
  • Home health
  • Power mobility devices
  • Hospice
Green means eligible to order or refer.

Enrollment records 2

Enrollment IDStateProvider typePAC IDDetails
I20200728000516 DC Practitioner - Hematology/Oncology 1052611431 Reassigns benefits to 2 organizations
I20210914003037 VA Practitioner - Hematology/OncologyPractitioner - Internal Medicine 1052611431 Reassigns benefits to 2 organizations

Care Compare profile

Medicare Care Compare
Specialty
Hematology/OncologyAlso: Internal Medicine
Education
Georgetown University School of Medicine, 2014
Medicare assignment
Accepts the Medicare-approved amount as payment in full
Telehealth
Offers telehealth services
Group practices
Inova Health Care ServicesGroup PAC ID 2466351093, 1,821 clinicians

Practice addresses (Care Compare)

3300 Gallows Rd
Falls Church, VA 22042-3307

3580 Joseph Siewick Dr
Fairfax, VA 22033-1764

3600 Joseph Siewick Dr
Fairfax, VA 22033-1709
Phone (703) 391-3600

44045 Rivderside Pkwy
Leesburg, VA 20176-5101

8081 Innovation Park Dr
Fairfax, VA 22031-4867

Hospital & facility affiliations

Merit-based Incentive Payment System (MIPS)

Final score
83.36 of 100Reported as group
Quality
73.03
Promoting interoperability
100
Improvement activities
40
Cost
71.49

National Provider Directory

National Provider Directory
Medicare enrollment (NPD)
Enrolled
Credentials
Doctor of Medicine

Practice roles

OrganizationSpecialtyStatusNew patients
Inova Health Care Services CurrentSince Aug 31, 2020 Accepting new patients
Inova Health Care Services Internal Medicine CurrentSince Sep 12, 2021 Accepting new patients

Locations

3300 Gallows Rd
Falls Church, VA 22042
Phone (703) 352-9395

224B Cornwall St NW
Leesburg, VA 20176
Phone (703) 771-2894

44055 Riverside Pkwy
Ste 108
Leesburg, VA 20176
Phone (703) 858-8600

Interoperability endpoints

  • Direct secure messaging: jallen680222@soc.inova.org

Organizations & group practices 3

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships, National Provider Directory roles and organizations whose NPPES authorized official is this provider.

Hospital & facility affiliations 8

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

NPI Registry JSON

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1396310400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1776816000000",
    "number": "1942628458",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "PO BOX 37174",
            "city": "BALTIMORE",
            "state": "MD",
            "postal_code": "212973174",
            "telephone_number": "571-423-5699",
            "fax_number": "571-423-5698"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "3580 JOSEPH SIEWICK DR STE 403",
            "city": "FAIRFAX",
            "state": "VA",
            "postal_code": "220331764",
            "telephone_number": "703-391-4395",
            "fax_number": "703-391-4394"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "8081 Innovation Park Dr",
            "address_purpose": "LOCATION",
            "city": "Fairfax",
            "state": "VA",
            "postal_code": "220314867",
            "country_code": "US",
            "telephone_number": "571-472-4724",
            "fax_number": "571-472-0241",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "ALLEN",
        "first_name": "JOSHUA",
        "middle_name": "M",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2014-04-01",
        "last_updated": "2026-04-22",
        "certification_date": "2026-04-22",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "VA",
            "license": "0101268640",
            "primary": false
        },
        {
            "code": "207RH0000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Hematology",
            "state": "VA",
            "license": "0101268640",
            "primary": false
        },
        {
            "code": "207RX0202X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Medical Oncology",
            "state": "VA",
            "license": "0101268640",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

Other providers in Fairfax, VA

Sources for this page

Verify at the official NPI Registry.