Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Alexander Gregers Posell, MD

Psychiatry Physician in Brooklyn, NY · enumerated 2020.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1598384315

Verified

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Registry record

Entity type Individual (Type 1)

Name Dr. Alexander Gregers Posell

Credential MD

Sex Male

Practice address 189 S 9th St Apt 20, Brooklyn, NY, 11211

Phone (213) 393-3711

Enumeration date Apr 11, 2020

Last updated in NPPES Dec 11, 2025

Taxonomy & licenses

2084P0800X Psychiatry Physician Allopathic & Osteopathic Physicians · License 319892 (NY) Primary

2084F0202X Forensic Psychiatry Physician Allopathic & Osteopathic Physicians · License 319892 (NY) Secondary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier	Type	State	Issuer
07808491	Medicaid	NY	-

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

Where does Alexander Posell practice?

The practice location on file with NPPES is in Brooklyn, NY. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Alexander Posell?

The National Provider Identifier (NPI) for Alexander Posell is 1598384315, a Type 1 (individual) record in the CMS NPPES registry.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-12-11.