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

DR. MARISSA DENNIS PHD
NPI 1841999067
Psychologist - Clinical in Boston, MA

Active since February 27, 2023PECOS Enrolled
300 LONGWOOD AVE, BOSTON, MA 02115(617) 355-6000 Get Directions Write a Review

NPPES record last updated: August 10, 2026. Verified against the NPPES registry weekly; last sync: August 23, 2026.

Record update history: Aug 10, 2026, Jul 22, 2026, May 30, 2025 and 1 more (4 updates tracked since 2023).

About Dr. Marissa Dennis Phd NPPES

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

DR. MARISSA DENNIS PHD (NPI 1841999067) is an individual clinical provider in Boston, Massachusetts, licensed in Massachusetts (PSY10001753) and active in the NPI registry since February 2023. She is enrolled in Medicare PECOS and maintains a secondary practice location in Brookline.

NPPES Registry Identity

NPI1841999067
Entity TypeIndividualFemale
Primary Taxonomy103TC0700X
Provider Legal NameDR. MARISSA DENNISCredential: PHD
Location Address300 LONGWOOD AVEBoston, MA 02115-5724
Mailing Address300 Longwood AveBoston, MA 02115-5724 · (617) 355-6000
Phone(617) 355-6000
Sole ProprietorYes
Enumeration DateFebruary 27, 2023
Last NPPES UpdateAugust 10, 20264 updates tracked since enumeration
NPPES CertifiedAugust 10, 2026
✔ NPI 1841999067 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 MA · PSY10001753
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.
300 LONGWOOD AVE, Boston, MA 02115
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Secondary Practice Location 1

Location 12 Brookline PlBrookline, MA 02445-7230 · Phone (617) 355-6000

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Marissa Dennis Phd 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.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 02115 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
$189.86 typical visit price
range $63.72 – $189.86
Typical copayment $47.46 (range $15.93 – $47.46)
Most-billed visit code 99205
Established Patient
$111.18 typical visit price
range $21.07 – $155.29
Typical copayment $27.79 (range $5.26 – $38.82)
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.

JULIE ANN HANSEN LCSW
Social Worker (Clinical)
300 LONGWOOD AVE
BOSTON, MA 02115
Suffolk County (857) 218-4309
MS. ANNA ROGLIERI
Nurse Practitioner (Psychiatric/Mental Health)
300 LONGWOOD AVE
BOSTON, MA 02115
Suffolk County (617) 355-6000
STEPHEN G. FLYNN M.D.
Anesthesiology (Pediatric Anesthesiology)
300 LONGWOOD AVE
BOSTON, MA 02115
Suffolk County (617) 355-6000
MRS. LAUREN ASHLEY SHARIS P.T., D.P.T
Physical Therapist
300 LONGWOOD AVE
BOSTON, MA 02115
Suffolk County (617) 355-7216
MS. SOYUN KWAN LICSW
Social Worker (Clinical)
300 LONGWOOD AVE, CHILDREN'S HOSPITAL BOSTON
BOSTON, MA 02115
Suffolk County (617) 355-0567
PUJA BANKA M.D.
Pediatrics
300 LONGWOOD AVE, BADER 203
BOSTON, MA 02115
Suffolk County (617) 355-6363
MR. COURTNEY SULLIVAN FRATTO CPNP
Nurse Practitioner (Pediatrics)
300 LONGWOOD AVE, HUNNEWELL BUILDING 322
BOSTON, MA 02115
Suffolk County (857) 218-4085
DR. ELIZABETH S TAGLAUER M.D., PH.D.
Pediatrics (Neonatal-Perinatal Medicine)
300 LONGWOOD AVE
BOSTON, MA 02115
Suffolk County (617) 355-6000

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 Marissa Dennis's NPI number?

The NPI number for Marissa Dennis is 1841999067. It was assigned to this individual provider in the NPPES registry on February 27, 2023.

Where is Marissa Dennis located?

Marissa Dennis practices at 300 Longwood Ave, Boston, MA 02115. The listed phone number is (617) 355-6000.

What is Marissa Dennis's specialty?

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

Is Marissa Dennis enrolled in Medicare?

Yes. Marissa Dennis is registered in the Medicare PECOS enrollment system.

When was this NPI record last updated?

The NPPES record for Marissa Dennis was last updated on August 10, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 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.