NPI registry status
Active
2026 NPPES data Gastroenterology Physician NPI 1639370919 MD
Verify on CMS → Youssef Assioun, MD
Gastroenterology Physician in Saint Louis, Missouri.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 16,567 in Gastroenterology Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
934
Medicare Part D claims · 476 beneficiaries · Gastroenterology Physician avg: 833
Generic prescribing
87%
generic claims · 13% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$1.8K
56 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Youssef Assioun, MD filed 934 Medicare Part D claims in 2023 as a Gastroenterology Physician in Saint Louis, Missouri, prescribing 87% generic.
- 934
- Part D claims, 2023
- 87%
- generic prescribing
- Likely
- board-certified (heuristic)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Youssef Assioun, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
934 Top 25% higher than 75% of 1,370,886 prescribers
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Medicare Part D Prescriber Public Use File · 2023
✓
Board certification likely (heuristic, not verified)
Youssef Assioun, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation - signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Youssef Assioun, MD?
Quality data not reportedPrimary specialty
Gastroenterology Physician
Medicare Part D claims
934 12% vs specialty avg
Specialty distribution in Missouri
How Gastroenterology Physician compares to other specialties among Missouri providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Gastroenterology Physician. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Youssef Assioun, MD appears in the CMS NPPES registry as a Gastroenterology Physician provider holding MD credentials at 10012 KENNERLY RD STE 102, Saint Louis, MO, 63128, with a listed phone of (314) 543-5911. NPI 1639370919 was issued on 05/31/2007.
Medicare Part D records for calendar year 2023 show 934 prescription claims written by this provider, covering 476 Medicare beneficiaries and totaling roughly $104K in drug spend, split 13% brand-name and 87% generic by claim count.
Gastroenterology Physician is a mid-sized specialty nationwide, with 16,567 enrolled providers across 54 states and an average of 833 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline.
Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist, always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1639370919 |
|---|---|
| Specialty | Gastroenterology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 05/31/2007 |
Hospital and facility affiliations
Facilities where Youssef Assioun, MD bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" - a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.
Mercy Clinic Gastroenterology LLC
Saint Louis, MO
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Industry payments received (2024) - CMS Open Payments transparency data
The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for Youssef Assioun, MD. Source: openpaymentsdata.cms.gov.
Total received
$1.8K
Largest payer
ABBVIE INC.
Most common payment type
Food and Beverage
Industry payments are not necessarily indicators of bias, they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.
Brand vs generic prescribing mix · Typical
Youssef Assioun, MD - brand share 13.0%
Gastroenterology Physician average
13% brand-name claims vs 87% generic, on 934 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
934
Total Claims
$104K
Total Drug Cost
476
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,329
- Total Day Supply
- 27,915
- Brand vs Generic
- 13% brand / 87% generic
- Brand Drug Cost
- $84K
- Generic Drug Cost
- $20K
Patient Demographics
- Average Patient Age
- 69.7 years
- Avg HCC Risk Score
- 1.39
- Gender Split
- 54% female / 46% male
- Age Distribution
- <65: 76, 65-74: 281, 75-84: 108, 85+: 11
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Youssef Assioun, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Pantoprazole Sodium
Pantoprazole Sodium
148 claims
- Omeprazole
Omeprazole
115 claims
- Famotidine 43
Famotidine
43 claims
- Linzess 41
Linzess
41 claims
- Esomeprazole Magne… 39
Esomeprazole Magnesium
39 claims
- Dicyclomine Hcl 30
Dicyclomine Hcl
30 claims
- Peg 3350-Electrolyte 27
Peg 3350-Electrolyte
27 claims
- Sutab 21
Sutab
21 claims
| Drug | Claims |
|---|---|
| Pantoprazole Sodium | 148 |
| Omeprazole | 115 |
| Famotidine | 43 |
| Linzess Linaclotide | 41 |
| Esomeprazole Magnesium | 39 |
| Dicyclomine Hcl | 30 |
| Peg 3350-Electrolyte Sodium Chloride/Nahco3/Kcl/Peg | 27 |
| Sutab Sod Sulf/Pot Chloride/Mag Sulf | 21 |
| Ibsrela Tenapanor Hcl | 13 |
| Gavilyte-C "Peg3350/Sod Sulf | N/A |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Gastroenterology Physician Overview
How Youssef Assioun, MD fits within the Gastroenterology Physician landscape nationally.
16,567
Gastroenterology Physician Providers in US
54
States with Gastroenterology Physician
833
Avg Claims per Provider
Youssef Assioun, MD's 934 claims are above the specialty average of 833.
Nearby Gastroenterology Physician Providers in Missouri
Other clinicians with the same primary specialty enrolled in Missouri, drawn from the same CMS NPPES roster as Assioun.
Dr. Ma'n Abdullah
MD
Columbia, MO
Dr. Kelsey Able
DO
Kansas City, MO
Dr. Barry Abramson
M.D.
Saint Louis, MO
Dr. Tarek Abu-Rajab Tamimi
M.D.
Kansas City, MO
Dr. Aireen-Ronalda Agulto
MD
Saint Louis, MO
Compare Gastroenterology Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Missouri medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Gastroenterology Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Youssef Assioun, MD's specialty? ▼
Youssef Assioun, MD specializes in Gastroenterology Physician and practices in Saint Louis, Missouri. Credentials: MD.
How much does Youssef Assioun, MD prescribe under Medicare Part D? ▼
In 2023, Youssef Assioun, MD wrote 934 Medicare Part D claims totaling $104K in drug costs for 476 beneficiaries.
Where is Youssef Assioun, MD located? ▼
Youssef Assioun, MD is located at 10012 KENNERLY RD STE 102, Saint Louis, MO, 63128. Phone: (314) 543-5911.
What is Youssef Assioun, MD's NPI number? ▼
Youssef Assioun, MD's National Provider Identifier (NPI) is 1639370919, issued on 05/31/2007.
Does Youssef Assioun, MD prescribe more brand-name or generic drugs? ▼
Youssef Assioun, MD's prescribing is 13% brand-name and 87% generic drugs by claim count, with $84K in brand drug costs.
How many Gastroenterology Physician providers are there in the US? ▼
There are 16,567 Gastroenterology Physician providers across 54 states in the US. The average Gastroenterology Physician provider writes 833 Medicare Part D claims per year.
What drugs does Youssef Assioun, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Youssef Assioun, MD's most frequently prescribed drugs include Pantoprazole Sodium, Omeprazole, Famotidine. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Youssef Assioun, MD accept Medicare? ▼
Youssef Assioun, MD appears in CMS Medicare data with 934 Part D claims and 476 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Youssef Assioun, MD's credentials? ▼
Youssef Assioun, MD's NPI is 1639370919 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Compiled from official public sources by the PlainDoctor editorial team.