William Jacob Wallach
Hospitalist Physician · Brooklyn, NY
William Jacob Wallach is a hospitalist physician with a practice address in Brooklyn, New York, and NPI 1720668551, issued on Apr 14, 2021. Check the license (New York 337791, as entered in NPPES) on the NYS Education Department, Office of the Professions; the Medicare figures below come from public CMS files.
- Name
- William Jacob Wallach
- Primary taxonomy
- Hospitalist Physician 208M00000X
- License number
- 337791 NY
Self-reported in NPPES; status is on the state search - Practice location
- 506 6TH St, Brooklyn, NY 11215
- Phone
- (646) 745-6369
- Enumerated
- Apr 14, 2021
- Record last updated
- Aug 20, 2025
- Medicare enrollment
- Enrolled (PECOS I20250925000255); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest hospitalist physician records → All 2,067 in New York → Look up another NPI →
Also registered at 506 6TH St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Haley Abbott, DDSStudent in an Organized Health Care Education/Training Program1568313161
- Jacob Abraham, MDStudent in an Organized Health Care Education/Training Program1043009665
- Maria Abraham, M.D.Pediatrics Physician1184039463
- Alexander Abramov, PA-CPhysician Assistant1487339511
- Eric Abrams, M.D.Emergency Medicine Physician1851737340
Verify William Jacob Wallach in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersNYS Education Department, Office of the Professions
Search for license 337791Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
75% fewer Medicare Part D claims than the average hospitalist physician in 2024
132 Medicare Part D claims for 32 beneficiaries, against an average of 521 among the 21,613 providers of this specialty who prescribed in Part D.
Most prescribed
- Duloxetine Hcl12 claims
- Pantoprazole Sodium11 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- Kings Physician Services PCBrooklyn, NY
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William Jacob Wallach among 2,067 hospitalist physician records in New York
William Jacob Wallach is one of 2,067 hospitalist physician records with a practice address in New York. 93% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2021, is newer than 83% of them.
- NPI issued2021 · 83% of these records are older, 11% newer
- In a Medicare fileYes · 93% of these records are
- In the CMS Doctors and Clinicians fileYes · 83% of these records are
- Graduated2022 · median 2013 among the 1,716 with a school on file
- Record last updated2025 · 37% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 208M00000X and a New York practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hospitalist Physician providers in New York
There are 2,067 hospitalist physician records in New York.
All 2,067 in New York → Every provider in Brooklyn → Hospitalist Physician nationwide →
The 8 hospitalist physician records with the nearest ZIP codes
- Amal AyoubBrooklyn, NY 112151386104164
- Kwesi Blackman, MDBrooklyn, NY 112151982164059
- Jenming Chen, M.D.Brooklyn, NY 112151245674787
- Dolcine Dalmacy, M.D.Brooklyn, NY 112151184664666
- Forough Hakimzada, M.D.Brooklyn, NY 112151699061804
- Asim Imam, MDBrooklyn, NY 112151205161320
- Frederic KarimBrooklyn, NY 112151619553682
- Kelly Liu, M.D.Brooklyn, NY 112151982896361
Common questions
What is William Jacob Wallach's NPI number?
William Jacob Wallach's National Provider Identifier (NPI) is 1720668551, issued on Apr 14, 2021. An NPI identifies a provider in billing; it is not a license.
Where is William Jacob Wallach located?
The NPPES record lists a practice address at 506 6TH St, Brooklyn, NY, 11215. Phone: (646) 745-6369. Providers update this record themselves, so call before visiting.
How can I verify William Jacob Wallach's license?
NPPES lists New York license number 337791, as entered by the provider. Search the NYS Education Department, Office of the Professions at https://www.op.nysed.gov/services/verifications/online-verification-searches. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William Jacob Wallach prescribe under Medicare Part D?
In 2024, William Jacob Wallach had 132 Medicare Part D claims for 32 beneficiaries; the average among hospitalist physician prescribers was 521. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.