Margaret Hayes, MD
NPI 1659545960 · Critical Care Medicine (Internal Medicine) Physician · Boston, MA
Enrolled with Medicare as Practitioner - Pulmonary Disease · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Margaret Hayes, MD is a Critical Care Medicine (Internal Medicine) Physician provider in Boston, MA (NPI 1659545960).
Provider details
- NPI number
- 1659545960
- Entity type
- Individual
- Primary specialty
- Critical Care Medicine (Internal Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- 263393 (MA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
18 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
220 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. 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.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Critical Care, First 30-74 Minutes99291 | 172 | $220 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 19 | $124 |
| Insertion of Non-Tunneled Central Venous Tube for Infusion (5 Years Or Older)36556 | 16 | $86 |
| Insertion of Artery Tube for Blood Sampling Or Infusion Through Skin36620 | 13 | $45 |
Typical Medicare-allowed amounts for these services range $45–$220 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2008-04-17
- Last updated
- 2016-08-24
Frequently asked questions
- What is Margaret Hayes's NPI number?
- Margaret Hayes's National Provider Identifier (NPI) is 1659545960, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Margaret Hayes's specialty?
- Margaret Hayes is listed in the NPPES registry with a primary specialty of Critical Care Medicine (Internal Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is Margaret Hayes located?
- Margaret Hayes's practice location on file with NPPES is 330 Brookline Ave, Boston, MA 02215.
- What is Margaret Hayes's phone number?
- The practice phone number listed in the NPPES registry for Margaret Hayes is (617) 667-5864.
- Does Margaret Hayes accept Medicare?
- Margaret Hayes is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Margaret Hayes's NPI active?
- Yes — Margaret Hayes's NPI (1659545960) is active in the NPPES registry as of the last update on 2016-08-24.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.