Marc B. Armstrong, M.D.
Internal Medicine Physician · Aberdeen, SD
Marc B. Armstrong, M.D. is an internal medicine physician with a practice address in Aberdeen, South Dakota, and NPI 1326453556, issued on Jun 26, 2014. Check the license (South Dakota 10781, as entered in NPPES) on the South Dakota Board of Medical and Osteopathic Examiners; the Medicare figures below come from public CMS files.
- Name
- Marc B. Armstrong
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- 10781 SD
TRN16984 FL
Self-reported in NPPES; status is on the state search - Practice location
- 305 S State St, Aberdeen, SD 57401
- Phone
- (605) 622-5100
- Enumerated
- Jun 26, 2014
- Record last updated
- Mar 17, 2018 (not updated in 8 years: call before relying on the address or phone)
- Fax
- (605) 622-4030
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 247 in South Dakota → Look up another NPI →
Also registered at 305 S State St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Marc B. Armstrong in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersSouth Dakota Board of Medical and Osteopathic Examiners
Search for license 10781Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
91% fewer Medicare Part D claims than the average internal medicine physician in 2024
286 Medicare Part D claims for 204 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 5% of claims. 52 claims were for opioids.
Most prescribed
- Oxycodone-Acetaminophen31 claims
- Methylprednisolone25 claims
- Ondansetron Odt22 claims
- Prednisone21 claims
- Nitrofurantoin Mono-Macro17 claims
- Cyclobenzaprine Hcl14 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.
No measured MIPS final score for 2023
CMS assigned the neutral MIPS final score of 75 without scoring Quality, Cost, Promoting Interoperability or Improvement Activities. It is an administrative threshold, so PlainDoctor does not compare it with measured clinicians.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Marc B. Armstrong among 247 internal medicine physician records in South Dakota
Marc B. Armstrong, M.D. is one of 247 internal medicine physician records with a practice address in South Dakota. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2014, is newer than 69% of them.
- NPI issued2014 · 69% of these records are older, 28% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileNo · 59% of these records are
- Record last updated2018 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a South Dakota practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
12 internal medicine physician records list a practice address in Aberdeen
They are 12 of the 758 NPPES records with a practice address in Aberdeen, and 247 internal medicine physician records in South Dakota.
All 247 in South Dakota → Every provider in Aberdeen → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Beenish Fayyaz, MDAberdeen, SD 574011649620675
- John Fritz, M.D.Aberdeen, SD 574011205870136
- Joan Harriott, MDAberdeen, SD 574011285927095
- Blake Heinz, D.O.Aberdeen, SD 574011871869172
- Nida MahamAberdeen, SD 574011689022584
- Arlin Myrmoe, M.D.Aberdeen, SD 574011184893349
- Ronald Rovang, M.D.Aberdeen, SD 574011295794378
- Denis Tcedilin, MDAberdeen, SD 574011053045591
Common questions
What is Marc B. Armstrong, M.D.'s NPI number?
Marc B. Armstrong, M.D.'s National Provider Identifier (NPI) is 1326453556, issued on Jun 26, 2014. An NPI identifies a provider in billing; it is not a license.
Where is Marc B. Armstrong, M.D. located?
The NPPES record lists a practice address at 305 S State St, Aberdeen, SD, 57401. Phone: (605) 622-5100. Providers update this record themselves, so call before visiting.
How can I verify Marc B. Armstrong, M.D.'s license?
NPPES lists South Dakota license number 10781, as entered by the provider. Search the South Dakota Board of Medical and Osteopathic Examiners at https://www.sdbmoe.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Marc B. Armstrong, M.D. prescribe under Medicare Part D?
In 2024, Marc B. Armstrong, M.D. had 286 Medicare Part D claims for 204 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Marc B. Armstrong, M.D.'s MIPS final score?
CMS assigned the neutral MIPS final score of 75 for 2023 without scoring any category, so it is not a measured result.
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.
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.