Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Mrs. Blake Rainie Slack, CNM, WHNP

Individual provider Midwife · NPI 1003055591

Mrs. Blake Rainie Slack, CNM, WHNP is registered under Certified Nurse Midwife (CNM) in Boston, Massachusetts. Qualified in 2008, 18 years ago. Practices with Massachusetts General Physicians Organization Inc, a 3,484-clinician group and accepts Medicare assignment. Licensed in Massachusetts and Maryland.

Years since qualifying
18
Licensed in
MA, MD
In the registry since
2009
Specialties on file
4
What do these letters mean?
CNM — Certified Nurse-Midwife
An advanced practice nurse who provides prenatal care and delivers babies.
WHNP — Women's Health Nurse Practitioner
A nurse practitioner specialising in women's health.

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Practice location Address checks out

55 Fruit St Founders 454 Massachusetts General Hospital
Boston, MA 02114-2621 Not confirmed with CMS for 10 years — call before visiting
Phone: (617) 726-2033
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Advanced Practice Midwife (primary) Taxonomy 367A00000X · Licence RN283129 (MA)
Midwife Taxonomy 176B00000X · Licence AC000650 (MD)
Midwife Taxonomy 176B00000X · Licence 283129 (MA)
Women's Health Nurse Practitioner Taxonomy 363LW0102X · Licence RN283129 (MA)

Record details

NPI number1003055591
Entity typeIndividual (Type 1)
GenderFemale
Credentials CNM , WHNP
Sole proprietorNo
NPI enumeratedFebruary 7, 2009
Last updated in NPPESApril 28, 2016

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyCERTIFIED NURSE MIDWIFE (CNM)
Medical schoolOTHER
Graduated 2008 (18 years in practice)
Group practice Massachusetts General Physicians Organization Inc — 3484 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients13
Services billed 25 a service is one billed item, such as a visit, a test or a procedure
Average patient age65

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Colleagues at Massachusetts General Physicians Organization Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 3484 clinicians in the practice; 12 are shown here.

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