NPPES file of Aug 9, 2026

Mallory Sin, LDN, RD

Registered Dietitian · Boston, MA

Mallory Sin, LDN, RD is a registered dietitian with a practice address in Boston, Massachusetts, and NPI 1821426826, issued on Oct 29, 2013. Check the license (Massachusetts 1076733, as entered in NPPES) with the Massachusetts board that licenses this profession; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1821426826
Name
Mallory Sin
Credential
LDN, RD
Primary taxonomy
Registered Dietitian 133V00000X
License number
1076733 MA
Self-reported in NPPES; status is on the state search
Practice location
One Joslin Place, Boston, MA 02215
Phone
(917) 825-0376
Enumerated
Oct 29, 2013
Record last updated
Nov 27, 2018 (not updated in 8 years: call before relying on the address or phone)
Medicare enrollment
Enrolled (PECOS I20190419000524); accepts Medicare assignment
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
Download card Updates feed

8 nearest registered dietitian records → All 2,244 in Massachusetts → Look up another NPI →

Also registered at One Joslin Place

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Lynn Abbott, RDRegistered Dietitian1699006601
  2. Paula Diaque Ballesteros, RDRegistered Dietitian1073876744
  3. Hala El Rami, MDStudent in an Organized Health Care Education/Training Program1003294869
  4. Lori Michelle Laffel, M.D.Pediatric Endocrinology Physician1275570228
  5. Alex Pisig, M.D.Retina Specialist (Ophthalmology) Physician1205361763
  6. Nora Saul, RDRegistered Dietitian1578592374

Verify Mallory Sin in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich Massachusetts board licenses this profession
    Search for license 1076733    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Find the Massachusetts license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

Is this page about you? You can ask us to correct, restrict or remove it: how.

Bills Medicare through one group practice

  1. Alisonrd LLCDedham, MA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Mallory Sin among 2,244 registered dietitian records in Massachusetts

Mallory Sin, LDN, RD is one of 2,244 registered dietitian records with a practice address in Massachusetts. 6% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2013, is newer than 37% of them.

  • NPI issued2013 · 37% of these records are older, 60% newer
  • In a Medicare fileYes · 6% of these records are
  • In the CMS Doctors and Clinicians fileYes · 9% of these records are
  • Graduated2012 · median 2011 among the 202 with a school on file
  • Record last updated2018 · 62% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 133V00000X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Registered Dietitian providers in Massachusetts

There are 2,244 registered dietitian records in Massachusetts.

All 2,244 in Massachusetts → Every provider in Boston → Registered Dietitian nationwide →

The 8 registered dietitian records with the nearest ZIP codes

  1. Sandra Allonen, RDBoston, MA 022151659404473
  2. Alison Books, MS, RD, LDNBoston, MA 022151568512671
  3. Kattia Corrales-Yauckoes, MS, RD, LDNBoston, MA 022151528073277
  4. Melinda Dennis, MS, RD, LDNBoston, MA 022151508920034
  5. Ann Feldman, MS, RD, CDEBoston, MA 022151457324386
  6. Melissa Gilman, RDBoston, MA 022151598738494
  7. Laurie Higgins, MS, RD, LDN, CDEBoston, MA 022151922022706
  8. Elisabeth Moore, R.D.Boston, MA 022151912063165

Common questions

What is Mallory Sin, LDN, RD's NPI number?

Mallory Sin, LDN, RD's National Provider Identifier (NPI) is 1821426826, issued on Oct 29, 2013. An NPI identifies a provider in billing; it is not a license.

Where is Mallory Sin, LDN, RD located?

The NPPES record lists a practice address at One Joslin Place, Boston, MA, 02215. Phone: (917) 825-0376. Providers update this record themselves, so call before visiting.

How can I verify Mallory Sin, LDN, RD's license?

NPPES lists Massachusetts license number 1076733, as entered by the provider. Search the Massachusetts board that licenses this profession; the NPPES record confirms identity only.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.