William M Klein, MD

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

205508 Issued in NY

Practice address

1 Hollow LN Ste 109
New Hyde Park, NY 11042-1215

Phone

(516) 627-4433

Fax

(516) 627-0552

NPI assigned

Jan 3, 2006

Sex

Male

Sole proprietor

No

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 1

Addresses

Other identifiers 8

Medicare fee-for-service enrollment

Enrolled in NY

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 1

Specialty

General Practice

Education

Icahn School of Medicine at Mount Sinai, 1994

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Telehealth

Offers telehealth services

Group practices

North Shore Primary Care Medical Associates PCGroup PAC ID 1456383165, 6 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• North Shore University Hospital Hospital, Manhasset, NY, CCN 330106

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: william.klein@900799988760580.direct.elationemr.com
• Direct secure messaging: wmk104pcs@m1461.primeclinicalsystems.direct-ci.com

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

• North Shore Primary Care Medical Associates, PC

  • Internal Medicine Physician
  • New Hyde Park, NY
  • NPI 1548287410
  Medicare reassignment Care Compare group NPD
• Health Bridge Concierge Medicine

  • Internal Medicine Physician
  • New Hyde Park, NY
  • NPI 1982439337
  NPD (past)

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

• North Shore University Hospital

  • General Acute Care Hospital
  • Manhasset, NY
  • NPI 1366459570
  Care Compare affiliation

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1136246400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1785974400000",
    "number": "1659359578",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1 HOLLOW LN STE 109",
            "city": "NEW HYDE PARK",
            "state": "NY",
            "postal_code": "110421215",
            "telephone_number": "516-627-4433",
            "fax_number": "516-627-0552"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1 HOLLOW LN STE 109",
            "city": "NEW HYDE PARK",
            "state": "NY",
            "postal_code": "110421215",
            "telephone_number": "516-627-4433",
            "fax_number": "516-627-0552"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "1000 Northern Blvd Ste 230",
            "address_purpose": "LOCATION",
            "city": "Great Neck",
            "state": "NY",
            "postal_code": "110215341",
            "country_code": "US",
            "telephone_number": "516-627-4433",
            "fax_number": "516-627-0552",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "KLEIN",
        "first_name": "WILLIAM",
        "middle_name": "M",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-01-03",
        "last_updated": "2026-08-06",
        "certification_date": "2026-08-06",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "NY",
            "license": "205508",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "VYTRA",
            "identifier": "136958",
            "state": null
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "CIGNA",
            "identifier": "3651757",
            "state": null
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "1199",
            "identifier": "A28929",
            "state": null
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "BLUE SHIELD",
            "identifier": "WK07R53510",
            "state": "NY"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "OXFORD",
            "identifier": "P3695174",
            "state": null
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "HIP",
            "identifier": "205508",
            "state": null
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "HEALTHNET",
            "identifier": "4C4799",
            "state": null
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "GHI",
            "identifier": "2594094",
            "state": null
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Gad E Klein, PHD
• Jonathan D S Klein, MD
• Karen E Klein
• Michael Norman Klein, DMD
• Pamela Eve Klein, M.D,
• Jake Alexander Kleinmahon, MD
• Abraham Klepfish
• Teineicia Knights, NP
• Denis Knobel, M.D.
• Caraline Kobel

• Internal Medicine Physician in New Hyde Park, NY
• Providers in New Hyde Park, NY by specialty
• Internal Medicine Physician in New York

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Aug 6, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.