Dr. Nathan Joseph Siesener, MD
- Medicare services, 2024
- 1,067
- Medicare patients, 2024
- 1,041
- Hospital affiliations
- 5
- Industry payments
- $16
- Medical groups
- 6
- Practice address
- One Memorial Drive, Alton, IL 62002
- Practice phone
- Call (314) 286-2227
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Siesener's professional email, personal email and mobile number
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Dr. Nathan Joseph Siesener is a diagnostic radiologist in Alton, Illinois
Dr. Siesener practices at Alton Memorial Hospital in Alton, Illinois, part of BJC Health.
Dr. Siesener's NPI, 1295239804, was assigned on March 19, 2018. Dr. Siesener graduated from University of Missouri, Columbia School of Medicine in 2018. Dr. Siesener holds Georgia license 94662.
- NPI
- 1295239804NPI Registry (opens in a new tab)
- Medicare PAC ID
- 7719216423
- NPI enumeration date
- March 19, 2018
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (314) 286-2227
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 34
- Medical school graduation
- 2018
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Nathan Joseph Siesener practices at 2 locations in Alton, Illinois
Dr. Siesener's primary practice is Alton Memorial Hospital, at One Memorial Drive, Alton, IL 62002 in Madison County. The practice phone is (314) 286-2227. Dr. Siesener also practices at Alton Memorial Hospital, 1 Memorial Dr, Alton, IL 62002.
- Alton Memorial HospitalPrimaryOne Memorial Drive, Alton, IL 62002 · Madison CountyPhone(314) 286-2227
- Alton Memorial Hospital1 Memorial Dr, Alton, IL 62002 · Madison CountyPhone(618) 463-7311
Sources: NPPES NPI Registry (CMS); Dmand AI Affiliation Data; and Dmand AI Practice Data
Dr. Nathan Joseph Siesener is affiliated with 5 sites of care and 6 medical groups
Dr. Siesener's primary practice is Alton Memorial Hospital in Alton, Illinois, part of BJC Health. Dr. Siesener is also affiliated with Barnes-Jewish Hospital. The medical group on file is WashU Medicine Physicians. Dmand AI also links Dr. Siesener to 3 more hospitals and 5 medical groups, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Nathan Joseph Siesener's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Siesener practices, 5 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Alton Memorial Hospital | Available with a free account |
| +4 more sites and 5 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Nathan Joseph Siesener is one of 1,336 diagnostic radiologists in Illinois
Diagnostic radiology is Dr. Siesener's primary specialty in the NPI Registry, under taxonomy code 2085R0202X. Dr. Siesener is licensed in Georgia.
Specialties and state licenses
- Diagnostic radiology, GeorgiaPrimary
Diagnostic radiologists near Dr. Siesener
Counts of diagnostic radiologists 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. Nathan Joseph Siesener billed Medicare for 1,067 services in 2024
CMS data shows 1,067 Medicare services from Dr. Siesener across 25 procedure codes in 2024, for 1,041 Medicare patients. Medicare paid $34,606 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Siesener's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Imaging
- 2023: 1712024: 1,044511%
- Tests and treatments
- 2023: 02024: 23
Dr. Siesener compared with the Illinois median for diagnostic radiologists, 2024
- Dr. Siesener
- Illinois median
- Medicare services
- 1,067vs 2,57559% below
- Medicare patients
- 1,041vs 1,83643% below
Medians across 1,261 diagnostic radiologists in Illinois with Dmand AI profiles that report each measure.
Dr. Siesener'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. Siesener and other diagnostic radiologists in Illinois.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Nathan Joseph Siesener treated 1,041 Medicare patients in 2024, average age 75
CMS counts 1,041 Medicare patients who saw Dr. Siesener in 2024. The largest group is 65 to 74, with 369 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 23% are also on Medicaid. Their average risk score is 1.99, 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. Siesener's median patient age at 70, with 58% women.
Dr. Siesener's Medicare patients by age, 2024
Dr. Siesener's Medicare patients by sex, 2024
- Women59657%
- Men44543%
Chronic conditions among Dr. Siesener's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis63%
- Ischemic heart disease52%
- Diabetes40%
- Chronic kidney disease38%
- Heart failure38%
- Anxiety37%
Share of Medicare patients with each condition. A patient can have several.
Dr. Siesener's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 70
Patient panel by sex, all payers
- Women58%
- Men41%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
How Dr. Nathan Joseph Siesener takes part in Medicare
Dr. Siesener 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. Nathan Joseph Siesener received $16 in industry payments in 2025
CMS Open Payments shows 1 general payment to Dr. Siesener from 1 drug or device company in 2025. Food and beverage make up the largest share, 100% of the total. Teleflex LLC paid the most, $16.
Companies that paid Dr. Siesener the most, 2025 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Nathan Joseph Siesener graduated from University of Missouri, Columbia School of Medicine
Dr. Siesener graduated from University of Missouri, Columbia School of Medicine in 2018.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Nathan Joseph Siesener'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 | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Affiliation DataDmand AI Practice 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) |
| 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. Nathan Joseph Siesener
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. Nathan Joseph Siesener's NPI number?
Dr. Nathan Joseph Siesener's NPI number is 1295239804. It was assigned on March 19, 2018, and it is active in the NPI Registry.
What kind of doctor is Dr. Nathan Joseph Siesener?
Dr. Nathan Joseph Siesener is a diagnostic radiologist in Alton, Illinois. The primary specialty in the NPI Registry is Diagnostic Radiology Physician (taxonomy code 2085R0202X).
Where does Dr. Nathan Joseph Siesener practice?
Dr. Siesener practices at One Memorial Drive, Alton, IL 62002. Dr. Siesener also practices at 1 Memorial Dr, Alton, IL 62002. Dr. Siesener's primary practice is Alton Memorial Hospital in Alton, Illinois, part of BJC Health. Dmand AI also links Dr. Siesener to 3 hospitals and 5 medical groups.
What is Dr. Nathan Joseph Siesener's office phone number?
The practice phone on file for Dr. Siesener is (314) 286-2227.
What is Dr. Nathan Joseph Siesener's medical license number?
Dr. Siesener holds Georgia license 94662.
Which hospitals is Dr. Nathan Joseph Siesener affiliated with?
Dr. Siesener practices at Alton Memorial Hospital in Alton, Illinois. Dr. Siesener is also affiliated with Barnes-Jewish Hospital. Dmand AI links Dr. Siesener to 3 more hospitals.
What medical group is Dr. Nathan Joseph Siesener part of?
Dr. Siesener is linked to WashU Medicine Physicians. Dmand AI links Dr. Siesener to 5 more medical groups.
Does Dr. Nathan Joseph Siesener accept Medicare?
Yes. CMS data shows Dr. Siesener billed Medicare for 1,067 services in 2024, and Dr. Siesener accepts Medicare assignment.
How many Medicare patients does Dr. Nathan Joseph Siesener see?
CMS counts 1,041 Medicare patients who saw Dr. Siesener in 2024, with an average age of 75.
What services does Dr. Nathan Joseph Siesener bill to Medicare?
In 2024, Dr. Siesener's most billed Medicare services were diagnostic imaging (71045), diagnostic imaging (71250) and diagnostic imaging (70450).
Show 3 more questionsShow fewer questions
Where did Dr. Nathan Joseph Siesener go to medical school?
Dr. Siesener graduated from University of Missouri, Columbia School of Medicine in 2018.
Has Dr. Nathan Joseph Siesener received payments from drug or device companies?
CMS Open Payments shows $16 in general payments to Dr. Siesener from 1 company from 2025 to 2025. The largest total came from Teleflex LLC.
How long has Dr. Nathan Joseph Siesener been practicing?
Dr. Siesener graduated from medical school in 2018, 8 years ago.
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