Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

SOPHIE ATWOOD MARSDEN LMHC
NPI 1316538499
Counselor - Mental Health in Boston, MA

Q: What is Sophie Marsden's NPI number?

The NPI number for Sophie Marsden is 1316538499. It was assigned to this individual provider in the NPPES registry on February 1, 2021. The provider is also known as Sophie Hollister Atwood Lmhc.

Q: What is Sophie Marsden's specialty?

The primary specialty registered for this NPI is Counselor, specializing in Mental Health, with taxonomy code 101YM0800X.

Q: When was this NPI record last updated?

The NPPES record for Sophie Marsden was last updated on September 16, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 days 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 February 01, 2021

105 W 3RD ST UNIT 2, BOSTON, MA 02127(617) 299-9220 Get Directions Write a Review

NPPES record last updated: September 16, 2026. Verified against the NPPES registry weekly; last sync: September 20, 2026.

Record update history: Sep 16, 2026, Sep 8, 2026, Feb 1, 2021 (3 updates tracked since 2021).

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About Sophie Atwood Marsden Lmhc NPPES

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

SOPHIE ATWOOD MARSDEN LMHC (NPI 1316538499) is an individual mental health provider in Boston, Massachusetts, licensed in Massachusetts (LMHC12912) and active in the NPI registry since February 2021.

NPPES Registry Identity

NPI1316538499

Entity TypeIndividualFemale

Primary Taxonomy101YM0800X

Provider Legal NameSOPHIE ATWOOD MARSDENCredential: LMHC

Location Address105 W 3RD ST UNIT 2Boston, MA 02127-4576

Mailing Address105 W 3rd St Unit 2Boston, MA 02127-4576 · (781) 801-9817

Phone(617) 299-9220

Sole ProprietorNo

Enumeration DateFebruary 1, 2021

Last NPPES UpdateSeptember 16, 20263 updates tracked since enumeration

NPPES CertifiedSeptember 16, 2026

✔ NPI 1316538499 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyCounselor · Mental HealthBehavioral Health & Social Service Providers

Taxonomy Code101YM0800X

License✔ Licensed in MA · LMHC12912

105 W 3RD ST UNIT 2, Boston, MA 02127

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Other Names 1

Professional Name (2)Sophie Hollister Atwood Lmhc

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 Sophie Marsden's NPI number?

The NPI number for Sophie Marsden is 1316538499. It was assigned to this individual provider in the NPPES registry on February 1, 2021. The provider is also known as Sophie Hollister Atwood Lmhc.

Where is Sophie Marsden located?

Sophie Marsden practices at 105 W 3rd St Unit 2, Boston, MA 02127. The listed phone number is (617) 299-9220.

What is Sophie Marsden's specialty?

The primary specialty registered for this NPI is Counselor, specializing in Mental Health, with taxonomy code 101YM0800X.

When was this NPI record last updated?

The NPPES record for Sophie Marsden was last updated on September 16, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 days 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.