Registry data as of Aug 27, 2026

Charles Longo, M.D.

Endocrinology, Diabetes & Metabolism Physician · Sioux Falls, SD

Charles Longo, M.D. is an endocrinology, diabetes & metabolism physician with a practice address in Sioux Falls, South Dakota, and NPI 1841266608, issued on Feb 23, 2006. Check the license (South Dakota 5192, as entered in NPPES) on the South Dakota Board of Medical and Osteopathic Examiners; the Medicare figures below come from public CMS files.

Record from CMS NPPES, loaded Aug 27, 2026 · Medicare files 2023 and 2024 · method · Verify with CMS →

NPPES recordas of Aug 27, 2026
1841266608
Name
Charles Longo
Credential
M.D.
Primary taxonomy
Endocrinology, Diabetes & Metabolism Physician 207RE0101X
License number
5192 SD
Self-reported in NPPES; status is on the state search
Practice location
1315 S. Cliff Ave, Sioux Falls, SD 57105
Phone
(605) 322-7600
Enumerated
Feb 23, 2006
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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Verify Charles Longo in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersSouth Dakota Board of Medical and Osteopathic Examiners
    Search for license 5192
    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 South Dakota 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.

32% more Medicare Part D claims than the average endocrinology, diabetes & metabolism physician in 2024

3,621 Medicare Part D claims for 334 beneficiaries, against an average of 2,739 among the 6,176 providers of this specialty who prescribed in Part D. Brand-name drugs were 46% of claims.

  1. Charles Longo3,621
  2. Specialty average2,739

Most prescribed

  1. Levothyroxine Sodium567 claims
  2. Ozempic270 claims
  3. Metformin Hcl185 claims
  4. Synthroid160 claims
  5. Novolog Flexpen111 claims
  6. Metformin Hcl Er110 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.

Industry payments in 2024: $68.19

4 payments, mostly food and beverage; the largest payer was Medtronic, Inc.. The 4,299 providers of this specialty with any payment received $6,068.67 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Charles Longo$68.19
  2. Specialty average$6,068.67

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

One hospital or facility affiliation

  1. Avera MckennanSioux Falls, SD

Source: CMS Doctors and Clinicians affiliations; Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.

Endocrinology, Diabetes & Metabolism Physician providers in South Dakota

There are 17 endocrinology, diabetes & metabolism physician records in South Dakota.

Other endocrinology, diabetes & metabolism physician records in South Dakota

  1. Richard Barth, M.D.Sioux Falls, SD1659375038
  2. William Blankenship, MDDakota Dunes, SD1104890888
  3. Lorayne Ann Chua, M.D.Sioux Falls, SD1700237914
  4. Richard Crawford, MDSioux Falls, SD1164528261
  5. Marie Angelica Diaz, M.D.Sioux Falls, SD1588072532
  6. Tracey Domangue, RNSioux Falls, SD1548139280
  7. Randall Fenner, M.D.Sioux Falls, SD1073780375
  8. Juliana Ferri Guerra, MDSioux Falls, SD1003435579
  9. Natalie Kappus, D.O.Sioux Falls, SD1649626037
  10. Sonalika Khachikian, MDRapid City, SD1699934067

Common questions

What is Charles Longo, M.D.'s NPI number?

Charles Longo, M.D.'s National Provider Identifier (NPI) is 1841266608, issued on Feb 23, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Charles Longo, M.D. located?

The NPPES record lists a practice address at 1315 S. Cliff Ave, Sioux Falls, SD, 57105. Phone: (605) 322-7600. Providers update this record themselves, so call before visiting.

How can I verify Charles Longo, M.D.'s license?

NPPES lists South Dakota license number 5192, 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 Charles Longo, M.D. prescribe under Medicare Part D?

In 2024, Charles Longo, M.D. had 3,621 Medicare Part D claims for 334 beneficiaries; the average among endocrinology, diabetes & metabolism physician prescribers was 2,739. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 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.

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.