Dr. Mark Andrew Nielsen, MD
- Medicare services, 2024
- 929
- Medicare patients, 2024
- 343
- Part D claims, 2024
- 297
- Hospital affiliations
- 1
- Industry payments
- $3,622
- Practice address
- 1325 S Cliff Ave Post Office Box 5045, Sioux Falls, SD 57117
- Practice phone
- Call (605) 322-8000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Nielsen's professional email, personal email and mobile number
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Dr. Mark Andrew Nielsen is an internist in Sioux Falls, South Dakota
Dr. Nielsen practices at Avera McKennan Hospital & University Health Center in Sioux Falls, South Dakota, part of Avera Health.
Dr. Nielsen's NPI, 1730152984, was assigned on February 8, 2006. Dr. Nielsen graduated from University of Nebraska College of Medicine in 1986. Dr. Nielsen holds Nebraska license 17897.
- NPI
- 1730152984NPI Registry (opens in a new tab)
- Medicare PAC ID
- 9436053071
- NPI enumeration date
- February 8, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (605) 322-8000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 66
- Medical school graduation
- 1986
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Mark Andrew Nielsen practices at Avera McKennan Hospital & University Health Center in Sioux Falls, South Dakota
Dr. Nielsen's primary practice is Avera McKennan Hospital & University Health Center, at 1325 S Cliff Ave Post Office Box 5045, Sioux Falls, SD 57117 in Minnehaha County. The practice phone is (605) 322-8000.
- Avera McKennan Hospital & University Health Center1325 S Cliff Ave Post Office Box 5045, Sioux Falls, SD 57117 · Minnehaha CountyPhone(605) 322-8000
Source: Dmand AI Affiliation Data
Dr. Mark Andrew Nielsen is affiliated with 1 site of care and 1 medical group
Dr. Nielsen's primary practice is Avera McKennan Hospital & University Health Center in Sioux Falls, South Dakota, part of Avera Health. The medical group on file is Avera McKennan Hospital & University Health Center.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Mark Andrew Nielsen's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Nielsen practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Avera McKennan Hospital & University Health Center | Available with a free account |
Source: Dmand AI Technology Install Data
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Dmand AI maps EHR vendors, IT decision makers and buying committees across Avera Health and 6.2K+ hospitals, with verified contacts in the same login.
Dr. Mark Andrew Nielsen is one of 267 internists in South Dakota
Internal medicine is Dr. Nielsen's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Nielsen is licensed in Nebraska.
Specialties and state licenses
- Internal medicine, NebraskaPrimary
Internists near Dr. Nielsen
Counts of internists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Mark Andrew Nielsen billed Medicare for 929 services in 2024
CMS data shows 929 Medicare services from Dr. Nielsen across 7 procedure codes in 2024, for 343 Medicare patients. Medicare paid $59,396 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Nielsen's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 8142024: 8687%
- Tests and treatments
- 2023: 172024: 61259%
Dr. Nielsen compared with the South Dakota median for internists, 2024
- Dr. Nielsen
- South Dakota median
- Medicare services
- 929vs 54271% above
- Medicare patients
- 343vs 23645% above
- Part D claims
- 124vs 124Close to median
Medians across 262 internists in South Dakota with Dmand AI profiles that report each measure.
Dr. Nielsen's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Nielsen and other internists in South Dakota.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Mark Andrew Nielsen treated 343 Medicare patients in 2024, average age 75
CMS counts 343 Medicare patients who saw Dr. Nielsen in 2024. The largest group is 65 to 74, with 126 patients. 75% of them have high blood pressure, and 74% have high cholesterol. 17% are also on Medicaid. Their average risk score is 2.08, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Nielsen's median patient age at 69, with 55% women.
Dr. Nielsen's Medicare patients by age, 2024
Dr. Nielsen's Medicare patients by sex, 2024
- Women17551%
- Men16849%
Chronic conditions among Dr. Nielsen's Medicare patients, 2024
- High blood pressure75%
- High cholesterol74%
- Arthritis52%
- Chronic kidney disease44%
- Mood disorders44%
- Anxiety40%
- Depression40%
- Diabetes37%
Share of Medicare patients with each condition. A patient can have several.
Dr. Nielsen's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 69
Patient panel by sex, all payers
- Women55%
- Men45%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Mark Andrew Nielsen wrote 297 Medicare Part D claims in 2024
In 2024, Dr. Nielsen wrote 297 Medicare Part D claims for 76 patients. 89% of them were for generic drugs. CMS names the drug for 124 of them, across 7 drugs with 11 or more claims each, at $12,398 in total drug cost. In 2023, CMS named 35 claims across 2 drugs.
Dr. Nielsen's Part D claims by kind of drug, 2024
- Generic263 claims89%
- Brand-name34 claims11%
Dr. Nielsen's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Nielsen's Part D claims, 2024
- Antibiotics7%22 of 297 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 352024: 124254%
Drugs named by CMS: 7 in 2024, 2 in 2023.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
How Dr. Mark Andrew Nielsen takes part in Medicare
Dr. Nielsen accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Mark Andrew Nielsen received $3,622 in industry payments from 2016 to 2024
CMS Open Payments shows 316 general payments to Dr. Nielsen from 23 drug and device companies from 2016 to 2024. Food and beverage make up the largest share, 96% of the total. GlaxoSmithKline, LLC. paid the most, $521.
General payments to Dr. Nielsen by program year, 2016 to 2024
General payments to Dr. Nielsen by kind, 2016 to 2024
- Food and beverage$3,47596%
- Education$1474%
Companies that paid Dr. Nielsen the most, 2016 to 2024
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Mark Andrew Nielsen graduated from University of Nebraska College of Medicine
Dr. Nielsen graduated from University of Nebraska College of Medicine in 1986.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Mark Andrew Nielsen's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Mark Andrew Nielsen
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Mark Andrew Nielsen's NPI number?
Dr. Mark Andrew Nielsen's NPI number is 1730152984. It was assigned on February 8, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Mark Andrew Nielsen?
Dr. Mark Andrew Nielsen is an internist in Sioux Falls, South Dakota. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Mark Andrew Nielsen practice?
Dr. Nielsen practices at 1325 S Cliff Ave Post Office Box 5045, Sioux Falls, SD 57117. Dr. Nielsen's primary practice is Avera McKennan Hospital & University Health Center in Sioux Falls, South Dakota, part of Avera Health.
What is Dr. Mark Andrew Nielsen's office phone number?
The practice phone on file for Dr. Nielsen is (605) 322-8000.
What is Dr. Mark Andrew Nielsen's medical license number?
Dr. Nielsen holds Nebraska license 17897.
Which hospitals is Dr. Mark Andrew Nielsen affiliated with?
Dr. Nielsen practices at Avera McKennan Hospital & University Health Center in Sioux Falls, South Dakota.
What medical group is Dr. Mark Andrew Nielsen part of?
Dr. Nielsen is linked to Avera McKennan Hospital & University Health Center.
Does Dr. Mark Andrew Nielsen accept Medicare?
Yes. CMS data shows Dr. Nielsen billed Medicare for 929 services in 2024, and Dr. Nielsen accepts Medicare assignment.
How many Medicare patients does Dr. Mark Andrew Nielsen see?
CMS counts 343 Medicare patients who saw Dr. Nielsen in 2024, with an average age of 75.
What services does Dr. Mark Andrew Nielsen bill to Medicare?
In 2024, Dr. Nielsen's most billed Medicare services were hospital inpatient care (99232), hospital inpatient care (99233) and hospital inpatient care (99239).
Show 4 more questionsShow fewer questions
Where did Dr. Mark Andrew Nielsen go to medical school?
Dr. Nielsen graduated from University of Nebraska College of Medicine in 1986.
What drugs does Dr. Mark Andrew Nielsen prescribe most?
In 2024 Medicare Part D data, Dr. Nielsen's most prescribed drugs by claims were Eliquis, Gabapentin and Oxcarbazepine.
Has Dr. Mark Andrew Nielsen received payments from drug or device companies?
CMS Open Payments shows $3,622 in general payments to Dr. Nielsen from 23 companies from 2016 to 2024. The largest total came from GlaxoSmithKline, LLC.
How long has Dr. Mark Andrew Nielsen been practicing?
Dr. Nielsen graduated from medical school in 1986, 40 years ago.
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