Provider Demographics
NPI:1780472407
Name:SIEFF, WILLIAM EDWARD II (MD)
Entity type:Individual
Prefix:DR
First Name:WILLIAM
Middle Name:EDWARD
Last Name:SIEFF
Suffix:II
Gender:
Credentials:MD
Other - Prefix:
Other - First Name:
Other - Middle Name:
Other - Last Name:
Other - Suffix:
Other - Last Name Type:
Other - Credentials:
Mailing Address - Street 1:373 BASSETT RD
Mailing Address - Street 2:
Mailing Address - City:NORTH HAVEN
Mailing Address - State:CT
Mailing Address - Zip Code:06473-1407
Mailing Address - Country:US
Mailing Address - Phone:203-584-8538
Mailing Address - Fax:
Practice Address - Street 1:1901 1ST AVE
Practice Address - Street 2:
Practice Address - City:NEW YORK
Practice Address - State:NY
Practice Address - Zip Code:10029-7494
Practice Address - Country:US
Practice Address - Phone:212-423-6262
Practice Address - Fax:
Is Sole Proprietor?:No
Enumeration Date:2025-04-30
Last Update Date:2025-04-30
Deactivation Date:
Deactivation Code:
Reactivation Date:
Provider Taxonomies
Primary?CodeTypeClassificationSpecialization
Yes390200000XStudent, Health CareStudent in an Organized Health Care Education/Training Program