DR. GILLIAN SLOANE MAYERSOHN PSY.D., ABPP
NPI 1265917884
Psychologist - Clinical in Saint Louis, MO

Q: What is Gillian Mayersohn's NPI number?

The NPI number for Gillian Mayersohn is 1265917884. It was assigned to this individual provider in the NPPES registry on September 28, 2018.

Q: What is Gillian Mayersohn's specialty?

The primary specialty registered for this NPI is Psychologist, specializing in Clinical, with taxonomy code 103TC0700X.

Q: When was this NPI record last updated?

The NPPES record for Gillian Mayersohn was last updated on April 28, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 months 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.

Active since September 28, 2018PECOS EnrolledAccepts Medicare Assignment

1465 S GRAND BLVD, SAINT LOUIS, MO 63104(314) 577-5667 Get Directions Write a Review

NPPES record last updated: April 28, 2025. Verified against the NPPES registry weekly; last sync: August 16, 2026.

Record update history: Nov 5, 2021, Sep 28, 2018 (2 updates tracked since 2018).

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About Dr. Gillian Sloane Mayersohn Psy.d., Abpp NPPES

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

DR. GILLIAN SLOANE MAYERSOHN PSY.D., ABPP (NPI 1265917884) is an individual clinical provider in Saint Louis, Missouri, licensed in Missouri (2018033534) and active in the NPI registry since September 2018. She is enrolled in Medicare PECOS, is affiliated with Ssm Health St Mary's Hospital - St Louis, and is a graduate of Other (2017).

NPPES Registry Identity

NPI1265917884

Entity TypeIndividualFemale

Primary Taxonomy103TC0700X

Provider Legal NameDR. GILLIAN SLOANE MAYERSOHNCredential: PSY.D., ABPP

Location Address1465 S GRAND BLVDSaint Louis, MO 63104-1003

Mailing Address1 Childrens Pl Ste 3n14Saint Louis, MO 63110-1002 · (314) 454-6069

Phone(314) 577-5667

Sole ProprietorNo

Medical School CMSOtherGraduated 2017

Enumeration DateSeptember 28, 2018

Last NPPES UpdateApril 28, 20252 updates tracked since enumeration

NPPES CertifiedApril 28, 2025

✔ NPI 1265917884 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPsychologist · ClinicalBehavioral Health & Social Service Providers

Taxonomy Code103TC0700X

License✔ Licensed in MO · 2018033534

Definition

A psychologist who provides continuing and comprehensive mental and behavioral health care for individuals and families; consultation to agencies and communities; training, education and supervision; and research-based practice. It is a specialty in breadth -- one that is broadly inclusive of severe psychopathology -- and marked by comprehensiveness and integration of knowledge and skill from a broad array of disciplines within and outside of psychology proper. The scope of clinical psychology encompasses all ages, multiple diversities and varied systems.

1465 S GRAND BLVD, Saint Louis, MO 63104

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Accepted Insurance

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

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Gillian Sloane Mayersohn Psy.d., Abpp 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.

PECOS PAC ID4183960263

PECOS Enrollment IDI20190110000785

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.

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Ssm Health St Mary's Hospital - St Louis

Acute Care Hospitals · Richmond Heights, MO

3/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number260091

Location6420 Clayton RdRichmond Heights, MO 63117 · St. Louis County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 63104 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

$169.38 typical visit price

range $55.65 – $169.38

Typical copayment $42.34 (range $13.91 – $42.34)

Most-billed visit code 99205

Established Patient

$98.37 typical visit price

range $17.76 – $137.92

Typical copayment $24.59 (range $4.44 – $34.48)

Most-billed visit code 99214

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.

DR. SARAH MARGARET HANLY PH.D.

Psychologist (Clinical)

1465 S GRAND BLVD
SAINT LOUIS, MO 63104

St. Louis City (314) 577-5667

KAVIPRIYA KOMESWARAN

Pediatrics (Pediatric Critical Care Medicine)

1465 S GRAND BLVD
SAINT LOUIS, MO 63104

St. Louis City (314) 617-2000

ALEXIS HAAS STEWART

Anesthesiologist Assistant

1465 S GRAND BLVD
SAINT LOUIS, MO 63104

St. Louis City (314) 977-5700

NATALIE DRURY RD, LD

Dietitian, Registered (Nutrition, Pediatric)

1465 S GRAND BLVD
SAINT LOUIS, MO 63104

St. Louis City (314) 577-5387

TIMOTHY J KUTZ MD

Pediatrics (Child Abuse Pediatrics)

1465 S GRAND BLVD
SAINT LOUIS, MO 63104

St. Louis City (314) 268-6406

CHRISTOPHER SALLEE MD

Pediatrics

1465 S GRAND BLVD
ST. LOUIS, MO 63104

St. Louis City (314) 577-1607

AMBER GRANA DO

Pediatrics (Pediatric Critical Care Medicine)

1465 S GRAND BLVD, DIVISION OF PEDIATRIC CRITICAL CARE
SAINT LOUIS, MO 63104

St. Louis City (314) 577-5695

DR. ETHAN EMIL PFEIFER MD

Student in an Organized Health Care Education/Training Program

1465 S GRAND BLVD
SAINT LOUIS, MO 63104

St. Louis City (314) 268-4070

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 Gillian Mayersohn's NPI number?

The NPI number for Gillian Mayersohn is 1265917884. It was assigned to this individual provider in the NPPES registry on September 28, 2018.

Where is Gillian Mayersohn located?

Gillian Mayersohn practices at 1465 S Grand Blvd, Saint Louis, MO 63104. The listed phone number is (314) 577-5667.

What is Gillian Mayersohn's specialty?

The primary specialty registered for this NPI is Psychologist, specializing in Clinical, with taxonomy code 103TC0700X.

Is Gillian Mayersohn enrolled in Medicare?

Yes. Gillian Mayersohn 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.

What insurance does Gillian Mayersohn accept?

Health plans from Medica list Gillian Mayersohn 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.

Is Gillian Mayersohn affiliated with any hospitals?

According to CMS data, Gillian Mayersohn is affiliated with Ssm Health St Mary's Hospital - St Louis.

When was this NPI record last updated?

The NPPES record for Gillian Mayersohn was last updated on April 28, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 months 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.