NPPES file of Aug 9, 2026

Mark I Chieh Hong, M.D

Nephrology Physician · Mason City, IA

Mark I Chieh Hong, M.D is a nephrology physician with a practice address in Mason City, Iowa, and NPI 1982048286, issued on Apr 17, 2013. Check the license (Iowa 42588, as entered in NPPES) on the Iowa Board of Medicine; 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
1982048286
Name
Mark I Chieh Hong
Credential
M.D
Primary taxonomy
Nephrology Physician 207RN0300X
License number
42588 IA
Self-reported in NPPES; status is on the state search
Practice location
1000 4TH St SW, Mason City, IA 50401
Phone
(641) 428-6999
Enumerated
Apr 17, 2013
Record last updated
Jul 15, 2025
Fax
(641) 428-6678
Medicare enrollment
Enrolled (PECOS I20150707000676); accepts Medicare assignment
Telehealth
Offers telehealth (CMS)
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.
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Also registered at 1000 4TH St SW

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

  1. Mohamed Abdi, MDRadiation Oncology Physician1982162608
  2. Luna Acharya, MDHospitalist Physician1609224674
  3. Jenna AdamsMental Health Counselor1407790710
  4. Sheela Ahari, MDAnesthesiology Physician1518910462
  5. Tauseef Akhtar, MDCardiovascular Disease Physician1508218009
  6. Emad Alamouti-Fard, MDFamily Medicine Physician1811821499

Verify Mark I Chieh Hong in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersIowa Board of Medicine
    Search for license 42588
    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 Iowa 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.

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5% more Medicare Part D claims than the average nephrology physician in 2024

1,541 Medicare Part D claims for 325 beneficiaries, against an average of 1,465 among the 10,986 providers of this specialty who prescribed in Part D. Brand-name drugs were 3% of claims.

  1. Mark Hong1,541
  2. Specialty average1,465

Most prescribed

  1. Calcitriol396 claims
  2. Furosemide149 claims
  3. Allopurinol129 claims
  4. Torsemide118 claims
  5. Losartan Potassium101 claims
  6. Nifedipine Er66 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.

2 hospitals and group practices

  1. Hancock County Health SystemBritt, IA · Critical Access Hospitals
  2. North Iowa Mercy ClinicsMason City, IA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through); hospitals matched to CMS Hospital General Information (Care Compare) (data.cms.gov).

Mark I Chieh Hong among 92 nephrology physician records in Iowa

Mark I Chieh Hong, M.D is one of 92 nephrology physician records with a practice address in Iowa. 84% 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 70% of them.

  • NPI issued2013 · 70% of these records are older, 29% newer
  • In a Medicare fileYes · 84% of these records are
  • In the CMS Doctors and Clinicians fileYes · 73% of these records are
  • Graduated2010 · median 2001 among the 67 with a school on file
  • Record last updated2025 · 48% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RN0300X and a Iowa practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Nephrology Physician providers in Iowa

There are 92 nephrology physician records in Iowa.

The 8 nephrology physician records with the nearest ZIP codes

  1. Arsalan Alvi, MDDes Moines, IA 503141972099570
  2. Prem Chandran, M.D.Des Moines, IA 503141518969104
  3. Patrick Chua, M.D.Des Moines, IA 503141043487937
  4. Siva Jagarlapudi, M.D.Des Moines, IA 503141770533952
  5. Robert Smith, D.O.Des Moines, IA 503141891746350
  6. Jobinson Thomas, M.D.Des Moines, IA 503141871530055
  7. Mark Belz, MDDes Moines, IA 503091427012061
  8. Kanwaljit Chouhan, MDDes Moines, IA 503091033384086

Common questions

What is Mark I Chieh Hong, M.D's NPI number?

Mark I Chieh Hong, M.D's National Provider Identifier (NPI) is 1982048286, issued on Apr 17, 2013. An NPI identifies a provider in billing; it is not a license.

Where is Mark I Chieh Hong, M.D located?

The NPPES record lists a practice address at 1000 4TH St SW, Mason City, IA, 50401. Phone: (641) 428-6999. Providers update this record themselves, so call before visiting.

How can I verify Mark I Chieh Hong, M.D's license?

NPPES lists Iowa license number 42588, as entered by the provider. Search the Iowa Board of Medicine at https://dial.iowa.gov/about-dial/boards-and-commissions/medicine. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does Mark I Chieh Hong, M.D prescribe under Medicare Part D?

In 2024, Mark I Chieh Hong, M.D had 1,541 Medicare Part D claims for 325 beneficiaries; the average among nephrology physician prescribers was 1,465. 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.

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.