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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.

GABRIEL ALFONSO NIEVES MD
NPI 1275113318
Psychiatry & Neurology - Psychiatry in Merrimack, NH

Active since April 13, 2021PECOS Enrolled
10 DUMAS LN, MERRIMACK, NH 03054(787) 637-9428 Get Directions Write a Review

NPPES record last updated: September 16, 2026. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Sep 16, 2026, Apr 13, 2021 (2 updates tracked since 2021).

About Gabriel Alfonso Nieves Md NPPES

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

GABRIEL ALFONSO NIEVES MD (NPI 1275113318) is an individual psychiatry provider in Merrimack, New Hampshire, licensed in Georgia (101446) and active in the NPI registry since April 2021. He is enrolled in Medicare PECOS and maintains 3 additional practice locations.

NPPES Registry Identity

NPI1275113318
Entity TypeIndividualMale
Primary Taxonomy2084P0800X
Provider Legal NameGABRIEL ALFONSO NIEVESCredential: MD
Location Address10 DUMAS LNMerrimack, NH 03054-2431
Mailing AddressPo Box 24449New York, NY 10087-0589 · (833) 351-8255
Phone(787) 637-9428
Sole ProprietorYes
Enumeration DateApril 13, 2021
Last NPPES UpdateSeptember 16, 20262 updates tracked since enumeration
NPPES CertifiedSeptember 16, 2026
✔ NPI 1275113318 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPsychiatry & Neurology · PsychiatryAllopathic & Osteopathic Physicians
Taxonomy Code2084P0800X
Licenses✔ Licensed in GA · 101446✔ Licensed in VA · 0101289937✔ Licensed in NY · 343110✔ Licensed in PR · 024175
Definition
A Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders and adjustment disorders. Biologic, psychological, and social components of illnesses are explored and understood in treatment of the whole person. Tools used may include diagnostic laboratory tests, prescribed medications, evaluation and treatment of psychological and interpersonal problems with individuals and families, and intervention for coping with stress, crises, and other problems.
10 DUMAS LN, Merrimack, NH 03054
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Secondary Practice Locations 3

Location 14550 N Point Pkwy Fl 2Alpharetta, GA 30022-2445 · Phone (833) 351-8255
Location 2109 W 27th St Rm 5SNew York, NY 10001-6208 · Phone (833) 351-8255
Location 3150 Riverside Pkwy Ste 115Fredericksburg, VA 22406-1094 · Phone (833) 351-8255

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Oscar Health, UnitedHealthcare.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Gabriel Alfonso Nieves Md 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.

Medicare Billing Reassignment

Medicare enrollment records show Gabriel Nieves reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Department Of Behavioral Health And Developmental Disabilities
867 mi
Psychiatric Hospital
3405 MIKE PADGETT HWY
Augusta, GA 30906
  • Reassigned Medicare billing, Georgia enrollment
  • 168 clinicians in this Medicare group
NPI 1093046005 (706) 792-7026

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 03054 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
$174.26 typical visit price
range $57.75 – $174.26
Typical copayment $43.56 (range $14.43 – $43.56)
Most-billed visit code 99205
Established Patient
$71.85 typical visit price
range $18.70 – $142.15
Typical copayment $17.96 (range $4.67 – $35.53)
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 Gabriel Nieves's NPI number?

The NPI number for Gabriel Nieves is 1275113318. It was assigned to this individual provider in the NPPES registry on April 13, 2021.

Where is Gabriel Nieves located?

Gabriel Nieves practices at 10 Dumas Ln, Merrimack, NH 03054. The listed phone number is (787) 637-9428.

What is Gabriel Nieves's specialty?

The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Psychiatry, with taxonomy code 2084P0800X.

Is Gabriel Nieves enrolled in Medicare?

Yes. Gabriel Nieves is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Gabriel Nieves's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Gabriel Nieves reassigns Medicare benefits to Department Of Behavioral Health And Developmental Disabilities (Augusta, GA). 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 Gabriel Nieves's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Gabriel Nieves accept?

Health plans from Oscar Health and UnitedHealthcare list Gabriel Nieves 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 Gabriel Nieves 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 38 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.