Colin Sieff, MB, BCH
NPI 1942382635 · Pediatric Hematology & Oncology Physician · Boston, MA
Enrolled with Medicare as Practitioner - Pediatric Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Colin Sieff, MB, BCH is a Pediatric Hematology & Oncology Physician provider in Boston, MA (NPI 1942382635).
Provider details
- NPI number
- 1942382635
- Entity type
- Individual
- Primary specialty
- Pediatric Hematology & Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MB, BCH
- Sex
- Male
- Sole proprietor
- No
- License
- 73641 (MA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-10-20
- Last updated
- 2007-07-08
Frequently asked questions
- What is Colin Sieff's NPI number?
- Colin Sieff's National Provider Identifier (NPI) is 1942382635, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Colin Sieff's specialty?
- Colin Sieff is listed in the NPPES registry with a primary specialty of Pediatric Hematology & Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Colin Sieff located?
- Colin Sieff's practice location on file with NPPES is 300 Longwood Ave, Boston, MA 02115-5724.
- What is Colin Sieff's phone number?
- The practice phone number listed in the NPPES registry for Colin Sieff is (617) 258-5228.
- Does Colin Sieff accept Medicare?
- Colin Sieff is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Colin Sieff's NPI active?
- Yes — Colin Sieff's NPI (1942382635) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.