1. Home
  2. Directory
  3. Virginia
  4. Alexandria
  5. Social Worker
  6. NPI Profile

SONJA FISCHER
NPI 1912425950
Social Worker - Clinical in Alexandria, VA

Active since August 30, 2017PECOS Enrolled
4850 MARK CENTER DR, ALEXANDRIA, VA 22311(703) 746-3530 Get Directions Write a Review

NPPES record last updated: June 18, 2024. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Jun 18, 2024, Aug 30, 2017 (2 updates tracked since 2017).

About Sonja Fischer NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

SONJA FISCHER (NPI 1912425950) is an individual clinical provider in Alexandria, Virginia, licensed in Virginia (0904009948) and active in the NPI registry since August 2017. She is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1912425950
Entity TypeIndividualFemale
Primary Taxonomy1041C0700X
Provider Legal NameSONJA FISCHER
Location Address4850 MARK CENTER DRAlexandria, VA 22311-1882
Mailing Address4850 Mark Center DrAlexandria, VA 22311-1882 · (703) 746-3400
Phone(703) 746-3530
Sole ProprietorNo
Enumeration DateAugust 30, 2017
Last NPPES UpdateJune 18, 20242 updates tracked since enumeration
NPPES CertifiedJune 18, 2024
✔ NPI 1912425950 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySocial Worker · ClinicalBehavioral Health & Social Service Providers
Taxonomy Code1041C0700X
License✔ Licensed in VA · 0904009948
Definition
A social worker who holds a master's or doctoral degree in social work from an accredited school of social work in addition to at least two years of post-master's supervised experience in a clinical setting. The social worker must be licensed, certified, or registered at the clinical level in the jurisdiction of practice. A clinical social worker provides direct services, including interventions focused on interpersonal interactions, intrapsychic dynamics, and life management issues. Clinical social work services are based on bio-psychosocial perspectives. Services consist of assessment, diagnosis, treatment (including psychotherapy and counseling), client-centered advocacy, consultation, evaluation, and prevention of mental illness, emotional, or behavioral disturbances.
4850 MARK CENTER DR, Alexandria, VA 22311
Open in Google Maps ↗

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Oscar Health.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Sonja Fischer is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment– Home Health Agency– Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignment

Medicare enrollment records show Sonja Fischer reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

City Of Alexandria
Same address
Mental Health (Including Community Mental Health Center)
4850 MARK CENTER DR
Alexandria, VA 22311
  • Reassigned Medicare billing, District of Columbia enrollment
  • 63 clinicians in this Medicare group
NPI 1447279658 (703) 746-3400

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 22311 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$0.00 typical visit price
range $65.18 – $194.86
Typical copayment $0.00 (range $16.29 – $48.71)
Most-billed visit code NA
Established Patient
$80.66 typical visit price
range $21.40 – $158.88
Typical copayment $20.16 (range $5.35 – $39.72)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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.

STEVEN E FRUTOS LCSW
Social Worker (Clinical)
4850 MARK CENTER DR
ALEXANDRIA, VA 22311
Alexandria City (703) 746-3400
MRS. ANJA D. BLACKADAR LCSW
Social Worker (Clinical)
4850 MARK CENTER DR
ALEXANDRIA, VA 22311
Alexandria City (703) 746-3400
SAMUEL OWUSU
Registered Nurse
4850 MARK CENTER DR
ALEXANDRIA, VA 22311
Alexandria City (703) 746-3400
JONATHAN TEUMER LCSW
Social Worker (Clinical)
4850 MARK CENTER DR
ALEXANDRIA, VA 22311
Alexandria City (703) 746-3400
PHENORIES MASSENBURG
Registered Nurse
4850 MARK CENTER DR
ALEXANDRIA, VA 22311
Alexandria City (703) 746-3400
JUANA OSORIO RAMIREZ
Psychologist (Clinical)
4850 MARK CENTER DR
ALEXANDRIA, VA 22311
Alexandria City (703) 746-3400
DR. ANJULI SARA JINDAL M.D.
Psychiatry & Neurology (Psychiatry)
4850 MARK CENTER DR
ALEXANDRIA, VA 22311
Alexandria City (703) 746-3400
NINA N ISKANDER LPC
Counselor (Professional)
4850 MARK CENTER DR
ALEXANDRIA, VA 22311
Alexandria City (703) 746-3400

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 Sonja Fischer's NPI number?

The NPI number for Sonja Fischer is 1912425950. It was assigned to this individual provider in the NPPES registry on August 30, 2017.

Where is Sonja Fischer located?

Sonja Fischer practices at 4850 Mark Center Dr, Alexandria, VA 22311. The listed phone number is (703) 746-3530.

What is Sonja Fischer's specialty?

The primary specialty registered for this NPI is Social Worker, specializing in Clinical, with taxonomy code 1041C0700X.

Is Sonja Fischer enrolled in Medicare?

Yes. Sonja Fischer is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Sonja Fischer's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Sonja Fischer reassigns Medicare benefits to City Of Alexandria (Alexandria, VA). The 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 Sonja Fischer's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Sonja Fischer accept?

Health plans from Oscar Health list Sonja Fischer as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

When was this NPI record last updated?

The NPPES record for Sonja Fischer was last updated on June 18, 2024. 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.