NPPES file of Aug 9, 2026

Mary Lynn Nielsen, M.D.

Psychiatry Physician · Clayton, MO

Mary Lynn Nielsen, M.D. is a psychiatry physician with a practice address in Clayton, Missouri, and NPI 1972645240, issued on Feb 13, 2007. Check the license (Missouri MDR7P10, as entered in NPPES) on the Missouri Board of Registration for the Healing Arts; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1972645240
Name
Mary Lynn Nielsen
Credential
M.D.
Primary taxonomy
Psychiatry Physician 2084P0800X
License number
MDR7P10 MO
Self-reported in NPPES; status is on the state search
Practice location
225 S Meramec Ave, Clayton, MO 63105
Phone
(314) 721-7550
Enumerated
Feb 13, 2007
Record last updated
Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
Fax
(314) 863-2114
Medicaid ID
F31343 MO
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 225 S Meramec Ave

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

  1. Michael Armour, PH.D.Clinical Psychologist1801001797
  2. Heather Barcroft, LPCCounselor1518299619
  3. Michael Brog, MDPsychiatry Physician1215016027
  4. Nicole Burnett, LPC, RPT, NBCC, MAProfessional Counselor1750775490
  5. Linda Cohn, M.S.W., L.C.S.W.Clinical Social Worker1790831659
  6. Charles Eckelman, PH.D.Clinical Psychologist1285755652

Verify Mary Lynn Nielsen in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMissouri Board of Registration for the Healing Arts
    Search for license MDR7P10    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
Open the Missouri license search

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55% fewer Medicare Part D claims than the average psychiatry physician in 2024

452 Medicare Part D claims for 35 beneficiaries, against an average of 1,000 among the 35,054 providers of this specialty who prescribed in Part D. Brand-name drugs were 5% of claims.

  1. Mary Nielsen452
  2. Specialty average1,000

Most prescribed

  1. Quetiapine Fumarate48 claims
  2. Alprazolam33 claims
  3. Trazodone Hcl30 claims
  4. Clonazepam28 claims
  5. Methylphenidate Hcl28 claims
  6. Bupropion Xl24 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

5 psychiatry physician records list a practice address in Clayton

They are 5 of the 403 NPPES records with a practice address in Clayton, and 965 psychiatry physician records in Missouri.

All 5 in Clayton → All 965 in Missouri → Every provider in Clayton →

Other psychiatry physician records in Missouri

  1. Elham Abbas, M.D.Raymore, MO1538509062
  2. Mehamed Abdi, MDColumbia, MO1821982224
  3. Nawfel Abdulameer, MDKansas City, MO1164818589
  4. Ahmed Abdulkadir, MDColumbia, MO1104496355
  5. Lachman Abichandani, M.D.St Louis, MO1508928342
  6. Balkozar Adam, M.D.Springfield, MO1053470948
  7. Wayne AdamsJoplin, MO1376478941
  8. Aniefiok Agarin, M.D.West Plains, MO1558611129
  9. Archna Aggarwal, M.D.Columbia, MO1649255936
  10. Sara AghaSaint Louis, MO1912585829

Common questions

What is Mary Lynn Nielsen, M.D.'s NPI number?

Mary Lynn Nielsen, M.D.'s National Provider Identifier (NPI) is 1972645240, issued on Feb 13, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Mary Lynn Nielsen, M.D. located?

The NPPES record lists a practice address at 225 S Meramec Ave, Clayton, MO, 63105. Phone: (314) 721-7550. Providers update this record themselves, so call before visiting.

How can I verify Mary Lynn Nielsen, M.D.'s license?

NPPES lists Missouri license number MDR7P10, as entered by the provider. Search the Missouri Board of Registration for the Healing Arts at https://www.fsmb.org/contact-a-state-medical-board/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does Mary Lynn Nielsen, M.D. prescribe under Medicare Part D?

In 2024, Mary Lynn Nielsen, M.D. had 452 Medicare Part D claims for 35 beneficiaries; the average among psychiatry physician prescribers was 1,000. Part D covers Medicare prescriptions 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.