Registry data as of Aug 27, 2026

Katherine O'Brien, RD, LDN

Registered Dietitian · Acton, MA

Katherine O'Brien, RD, LDN is a registered dietitian with a practice address in Acton, Massachusetts, and NPI 1588129639, issued on Feb 4, 2019. Check the license (Massachusetts 4418, as entered in NPPES) with the Massachusetts board that licenses this profession; the federal record below is the public data PlainDoctor holds for this provider.

Record from CMS NPPES, loaded Aug 27, 2026 · method · Verify with CMS →

NPPES recordas of Aug 27, 2026
1588129639
Name
Katherine O'Brien
Credential
RD, LDN
Primary taxonomy
Registered Dietitian 133V00000X
License number
4418 MA
Self-reported in NPPES; status is on the state search
Practice location
321 Main St, Acton, MA 01720
Phone
(978) 635-8700
Enumerated
Feb 4, 2019
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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Also registered at 321 Main St

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

  1. Christopher Bechtel, NPNurse Practitioner1144578626
  2. Meryl BergerNurse Practitioner1922600220
  3. Louis Berk, M.D.Family Medicine Physician1730501875
  4. Elizabeth Berman, RDN, LDNRegistered Dietitian1679949143
  5. Christine Brown, M.D.Internal Medicine Physician1588861660
  6. Samuel BrownClinical Social Worker1336576065

Verify Katherine O'Brien 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 4418
    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.

17 registered dietitian records list a Acton practice address

They are 17 of the 556 NPPES records with a Acton practice address, and 2,202 registered dietitian records in Massachusetts. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

Other registered dietitian records in Massachusetts

  1. Lynn Abbott, RDBoston, MA1699006601
  2. Lauren Abeles, RD, RDNNeedham, MA1407621311
  3. Robin Abourizk, MA, MS, RD, LDNBoston, MA1073846945
  4. Christine Abrahamian, R.D.Framingham, MA1114149895
  5. Jenica Abram, MPH, RDN, LDNConcord, MA1891554325
  6. Jennifer Ackerman, MS, RD, LDN, CDEWinchester, MA1538349097
  7. Amy Adams, RDBrockton, MA1033976048
  8. Karin AdamsMarblehead, MA1316531502
  9. Rachel Adams, RDNMarblehead, MA1770438590
  10. Sarah Adler, MS RDN LDNBoston, MA1821741489

Common questions

What is Katherine O'Brien, RD, LDN's NPI number?

Katherine O'Brien, RD, LDN's National Provider Identifier (NPI) is 1588129639, issued on Feb 4, 2019. An NPI identifies a provider in billing; it is not a license.

Where is Katherine O'Brien, RD, LDN located?

The NPPES record lists a practice address at 321 Main St, Acton, MA, 01720. Phone: (978) 635-8700. Providers update this record themselves, so call before visiting.

How can I verify Katherine O'Brien, RD, LDN's license?

NPPES lists Massachusetts license number 4418, 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), loaded Aug 27, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.

Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 27, 2026.