Mallory Sin, LDN, RD
NPI 1821426826 · Registered Dietitian · Boston, MA
Enrolled with Medicare as Practitioner - Registered Dietitian Or Nutrition Professional · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mallory Sin, LDN, RD is a Registered Dietitian provider in Boston, MA (NPI 1821426826).
Provider details
- NPI number
- 1821426826
- Entity type
- Individual
- Primary specialty
- Registered DietitianDietary & Nutritional Service Providers
- Credential
- LDN, RD
- Sex
- Female
- Sole proprietor
- No
- License
- 1076733 (MA)
Specialties & taxonomies
Dietary & Nutritional Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
12 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
77 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) |
|---|---|---|
| Therapy Procedure for Nutrition Management, Each 15 Minutes97802 | 77 | $34 |
Typical Medicare-allowed amounts for these services range $34–$34 (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
Additional practice locations (1)
- 1290 Tremont StRoxbury, MA 02120-3432Phone: (617) 427-1000
Registry dates
- Enumerated
- 2013-10-29
- Last updated
- 2018-11-27
Frequently asked questions
- What is Mallory Sin's NPI number?
- Mallory Sin's National Provider Identifier (NPI) is 1821426826, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mallory Sin's specialty?
- Mallory Sin is listed in the NPPES registry with a primary specialty of Registered Dietitian (Dietary & Nutritional Service Providers).
- Where is Mallory Sin located?
- Mallory Sin's practice location on file with NPPES is One Joslin Place, Boston, MA 02215-3432.
- What is Mallory Sin's phone number?
- The practice phone number listed in the NPPES registry for Mallory Sin is (917) 825-0376.
- Does Mallory Sin accept Medicare?
- Mallory Sin is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mallory Sin's NPI active?
- Yes — Mallory Sin's NPI (1821426826) is active in the NPPES registry as of the last update on 2018-11-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.