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

WILLIAM M KLEIN MD
NPI 1659359578
Internal Medicine in New Hyde Park, NY

Active since January 03, 2006PECOS Enrolled
1 HOLLOW LN STE 109, NEW HYDE PARK, NY 11042(516) 627-4433(516) 627-0552 Get Directions Write a Review

NPPES record last updated: August 6, 2026. Verified against the NPPES registry weekly; last sync: August 09, 2026.

About William M Klein Md NPPES

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

WILLIAM M KLEIN MD (NPI 1659359578) is an individual internal medicine provider in New Hyde Park, New York, licensed in New York (205508) and active in the NPI registry since January 2006. He is enrolled in Medicare PECOS, is affiliated with North Shore University Hospital, and maintains a secondary practice location in Great Neck.

NPPES Registry Identity

NPI1659359578
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameWILLIAM M KLEINCredential: MD
Location Address1 HOLLOW LN STE 109New Hyde Park, NY 11042-1215
Mailing Address1 Hollow Ln Ste 109New Hyde Park, NY 11042-1215 · (516) 627-4433 · Fax (516) 627-0552
Fax(516) 627-0552
Sole ProprietorNo
Medical School CMSIcahn School Of Medicine At Mount SinaiGraduated 1994
Enumeration DateJanuary 3, 2006
Last NPPES UpdateAugust 6, 2026
NPPES CertifiedAugust 6, 2026
NPI 1659359578 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License Licensed in NY · 205508
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
1 HOLLOW LN STE 109, New Hyde Park, NY 11042

Secondary Practice Location 1

Location 11000 Northern Blvd Ste 230Great Neck, NY 11021-5341 · Phone (516) 627-4433 · Fax (516) 627-0552

Other Identifiers 8

Other136958Vytra
Other3651757Cigna
OtherA289291199
OtherWK07R53510NY · Blue Shield
OtherP3695174Oxford
Other205508Hip
Other4C4799Healthnet
Other2594094Ghi

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

Enrolled in Medicare and accepts Medicare assignment

William M Klein Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID8123050564
PECOS Enrollment IDI20050907000059
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.

Areas of Expertise CMS Part B claims 22

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
997 services189 patients
Insertion of needle into vein for collection of blood sample 36415
This procedure involves inserting a small needle into a vein, typically in your arm, to collect a blood sample. It's a quick and simple process to help diagnose or monitor health conditions. You may feel a small prick, but discomfort is minimal.
591 services187 patients
Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 93000
An electrocardiogram (ECG) is a non-invasive test that records your heart's electrical activity. Using 12 leads attached to your body, it captures data to help identify heart conditions. A doctor interprets the results and provides a report.
235 services178 patients
Injection of drug or substance under skin or into muscle 96372
This procedure involves administering medication directly under the skin or into a muscle. A small needle is used to inject the drug, allowing it to be absorbed quickly into the bloodstream. It's a common method for delivering a variety of medications.
166 services40 patients
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit G0439
An annual wellness visit is a yearly appointment with your primary care provider to create or update a personalized prevention plan. This plan helps prevent illness based on your current health and risk factors. It's a subsequent visit, meaning it follows an initial assessment.
138 services138 patients
Detection test by immunoassay with direct visual observation for severe acute respiratory syndrome coronavirus 2 (covid-19) 87811
This is a test to detect COVID-19, the virus causing severe respiratory illness. It uses a method called immunoassay, which identifies the virus by its unique proteins. The test is directly observed for accuracy. It helps determine if you're currently infected.
127 services78 patients

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

North Shore University Hospital

Acute Care Hospitals · Manhasset, NY
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number330106
Location300 Community DriveManhasset, NY 11030 · Nassau County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 11042 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
$154.28 typical visit price
range $67.40 – $203.53
Typical copayment $38.57 (range $16.85 – $50.88)
Most-billed visit code 99204
Established Patient
$117.62 typical visit price
range $21.66 – $164.45
Typical copayment $29.40 (range $5.41 – $41.11)
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.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

Reported Quality Measures

e-Prescribing
At least one permissible prescription written by the MIPS eligible clinician is queried for a drug formulary and transmitted electronically using certified EHR technology.
100%1,923 patients5/55-star benchmark: 100%
Health Information Exchange
The MIPS eligible clinician that transitions or refers their patient to another setting of care or health care clinician (1) uses CEHRT to create a summary of care record; and (2) electronically transmits such summary to a receiving health care clinician for…
25%550 patients2/55-star benchmark: 96%
Medication Reconciliation
The MIPS eligible clinician performs medication reconciliation for at least one transition of care in which the patient is transitioned into the care of the MIPS eligible clinician.
100%398 patients5/55-star benchmark: 100%
Patient-Specific Education
The MIPS eligible clinician must use clinically relevant information from CEHRT to identify patient-specific educational resources and provide access to those materials to at least one unique patient seen by the MIPS eligible clinician.
89%558 patients4/55-star benchmark: 99%
Provide Patient Access
At least one patient seen by the MIPS eligible clinician during the performance period is provided timely access to view online, download, and transmit to a third party their health information subject to the MIPS eligible clinician's discretion to withhold…
93%558 patients4/55-star benchmark: 100%
Secure Messaging
For at least one unique patient seen by the MIPS eligible clinician during the performance period, a secure message was sent using the electronic messaging function of CEHRT to the patient (or the patient-authorized representative), or in response to a secure…
1%558 patients1/55-star benchmark: 59%
Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Referred Medical Equipment & Supplies CMS DME claims 2

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390
DME-Oxygen and Supplies · category DC002N
2 suppliers20 claims20 services$67.95 avg. paid by Medicare
Supply allowance for therapeutic continuous glucose monitor (cgm), includes all supplies and accessories, 1 month supply = 1 unit of service K0553
DME-Other DME · category DE017N
3 suppliers14 claims14 services$213.11 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 4

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

Internal Medicine
1 HOLLOW LN STE 109
NEW HYDE PARK, NY 11042
Internal Medicine
1 HOLLOW LN STE 109
NEW HYDE PARK, NY 11042
Family Medicine
1 HOLLOW LN STE 109
NEW HYDE PARK, NY 11042
Internal Medicine
1 HOLLOW LN STE 109
NEW HYDE PARK, NY 11042

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 William Klein's NPI number?

The NPI number for William Klein is 1659359578. It was assigned to this individual provider in the NPPES registry on January 3, 2006.

Where is William Klein located?

William Klein practices at 1 Hollow Ln Ste 109, New Hyde Park, NY 11042. The listed phone number is (516) 627-4433.

What is William Klein's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is William Klein enrolled in Medicare?

Yes. William Klein is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Is William Klein affiliated with any hospitals?

According to CMS data, William Klein is affiliated with North Shore University Hospital.

When was this NPI record last updated?

The NPPES record for William Klein was last updated on August 6, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 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.