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

MRS. GRETCHEN DORR HORST LCSW
NPI 1104913821
Social Worker - Clinical in Herndon, VA

Active since October 05, 2006PECOS Enrolled
429B CARLISLE DR # 205, HERNDON, VA 20170(703) 391-7380(703) 783-8655 Get Directions Write a Review

NPPES record last updated: June 28, 2024. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Mrs. Gretchen Dorr Horst Lcsw NPPES

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

MRS. GRETCHEN DORR HORST LCSW (NPI 1104913821) is an individual clinical provider in Herndon, Virginia, licensed in Virginia (0904001567) and active in the NPI registry since October 2006. She is enrolled in Medicare PECOS and is a graduate of Other (1980).

NPPES Registry Identity

NPI1104913821
Entity TypeIndividualFemale
Primary Taxonomy1041C0700X
Provider Legal NameMRS. GRETCHEN DORR HORSTCredential: LCSW
Location Address429B CARLISLE DR # 205Herndon, VA 20170-4802
Mailing Address429b Carlisle Dr # 205Herndon, VA 20170-4802 · (703) 391-7380 · Fax (703) 783-8655
Phone(703) 391-7380
Fax(703) 783-8655
Sole ProprietorNo
Medical School CMSOtherGraduated 1980
Enumeration DateOctober 5, 2006
Last NPPES UpdateJune 28, 2024
NPPES CertifiedJune 28, 2024
✔ NPI 1104913821 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 · 0904001567
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.
429B CARLISLE DR # 205, Herndon, VA 20170
Open in Google Maps ↗

Other Identifiers 1

Other102938VA · Anthem

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)

Mrs. Gretchen Dorr Horst Lcsw is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID5395715122
PECOS Enrollment IDI20040729000312
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 Gretchen Horst reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

The Dorr Center, LLC
1.1 mi
Clinical
11870 SUNRISE VALLEY DR, 200
Reston, VA 20191
  • Reassigned Medicare billing, District of Columbia enrollment
NPI 1467549188 (703) 391-7380

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.

Psychotherapy, 45 minutes 90834
Psychotherapy is a treatment method where you converse with a therapist about your thoughts, feelings, and behaviors. In a 45-minute session, the therapist assists you in understanding and managing your mental health concerns, improving emotional wellness, and promoting personal growth.
343 services15 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 20170 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.

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 Gretchen Horst's NPI number?

The NPI number for Gretchen Horst is 1104913821. It was assigned to this individual provider in the NPPES registry on October 5, 2006.

Where is Gretchen Horst located?

Gretchen Horst practices at 429B Carlisle Dr # 205, Herndon, VA 20170. The listed phone number is (703) 391-7380.

What is Gretchen Horst's specialty?

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

Is Gretchen Horst enrolled in Medicare?

Yes. Gretchen Horst is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Gretchen Horst's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Gretchen Horst reassigns Medicare benefits to The Dorr Center, LLC (Reston, 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 Gretchen Horst's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Gretchen Horst accept?

Health plans from Oscar Health list Gretchen Horst 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 Gretchen Horst was last updated on June 28, 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.