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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. ALLISON L. BAIER PHD
NPI 1821619313
Psychologist - Clinical in Lexington, MA

Active since May 06, 2020Opted out of Medicare · through Jan 27, 2027
10 MUZZEY ST STE 9, LEXINGTON, MA 02421(978) 831-9726 Get Directions Write a Review

NPPES record last updated: September 18, 2026. Verified against the NPPES registry weekly; last sync: September 27, 2026.

Record update history: Sep 18, 2026, Jan 10, 2025, Nov 3, 2023 and 1 more (4 updates tracked since 2020).

About Dr. Allison L. Baier Phd NPPES

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

DR. ALLISON L. BAIER PHD (NPI 1821619313) is an individual clinical provider in Lexington, Massachusetts, licensed in Massachusetts (PSY10000301) and active in the NPI registry since May 2020. She has opted out of Medicare through January 27, 2027 and remains eligible to order and refer.

NPPES Registry Identity

NPI1821619313
Entity TypeIndividualFemale
Primary Taxonomy103TC0700X
Provider Legal NameDR. ALLISON L. BAIERCredential: PHD
Location Address10 MUZZEY ST STE 9Lexington, MA 02421-5200
Mailing Address10 Muzzey St Ste 9Lexington, MA 02421-5200 · (978) 831-9726
Phone(978) 831-9726
Sole ProprietorNo
Enumeration DateMay 6, 2020
Last NPPES UpdateSeptember 18, 20264 updates tracked since enumeration
NPPES CertifiedSeptember 18, 2026
✔ NPI 1821619313 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 · PSY10000301
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.
10 MUZZEY ST STE 9, Lexington, MA 02421
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Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

ⓘ

Opted out of Medicare

Dr. Allison L. Baier Phd has filed a Medicare opt-out affidavit. Services are provided under private contract between the provider and the patient, and are not billed to or reimbursed by Medicare. The opt-out is on file from January 27, 2025 through January 27, 2027.

Opt-Out Effective DateJanuary 27, 2025
Opt-Out In Effect ThroughJanuary 27, 2027Opt-out affidavits renew automatically every two years unless cancelled
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment– Home Health Agency– Power Mobility DevicesAn opted-out provider can still order and refer for Medicare patients in the categories marked above, even though their own services are not covered.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 02421 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 3

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

BENJAMIN BILLINGSLEY PHD
Psychologist (Clinical)
10 MUZZEY ST STE 9
LEXINGTON, MA 02421
Middlesex County (914) 462-8338
NAMAPSYCH
Nurse Practitioner (Psychiatric/Mental Health)
10 MUZZEY ST STE 9
LEXINGTON, MA 02421
Middlesex County (351) 333-0507
MRS. AMANDA LYN SHEEHAN PMHNP-BC, FNP-BC
Nurse Practitioner (Psychiatric/Mental Health)
10 MUZZEY ST STE 9
LEXINGTON, MA 02421
Middlesex County (351) 333-0507

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 Allison Baier's NPI number?

The NPI number for Allison Baier is 1821619313. It was assigned to this individual provider in the NPPES registry on May 6, 2020.

Where is Allison Baier located?

Allison Baier practices at 10 Muzzey St Ste 9, Lexington, MA 02421. The listed phone number is (978) 831-9726.

What is Allison Baier's specialty?

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

Is Allison Baier enrolled in Medicare?

No. Allison Baier has opted out of Medicare through January 27, 2027. Care is provided under private contracts, and Medicare does not pay for services furnished by providers who have opted out. The provider remains eligible to order and refer services for Medicare patients.

When was this NPI record last updated?

The NPPES record for Allison Baier was last updated on September 18, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 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.