DR. MICHAEL ANSSTAS M.D.
NPI 1851658728
Internal Medicine - Gastroenterology in Saint Louis, MO

Q: What is Michael Ansstas's NPI number?

The NPI number for Michael Ansstas is 1851658728. It was assigned to this individual provider in the NPPES registry on April 17, 2012.

Q: What is Michael Ansstas's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Q: When was this NPI record last updated?

The NPPES record for Michael Ansstas was last updated on October 27, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since April 17, 2012PECOS EnrolledAccepts Medicare Assignment

11155 DUNN RD STE 309E, SAINT LOUIS, MO 63136(314) 953-8799 Get Directions Write a Review

NPPES record last updated: October 27, 2025. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Feb 23, 2022, Feb 5, 2021, Jul 22, 2020 and 1 more (4 updates tracked since 2019).

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About Dr. Michael Ansstas M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. MICHAEL ANSSTAS M.D. (NPI 1851658728) is an individual gastroenterology provider in Saint Louis, Missouri, licensed in Missouri (2012032351) and active in the NPI registry since April 2012. He is enrolled in Medicare PECOS, is affiliated with Archbold Memorial, and maintains 2 additional practice locations.

NPPES Registry Identity

NPI1851658728

Entity TypeIndividualMale

Primary Taxonomy207RG0100X

Provider Legal NameDR. MICHAEL ANSSTASCredential: M.D.

Location Address11155 DUNN RD STE 309ESaint Louis, MO 63136-6111

Mailing Address11155 Dunn Rd Ste 309eSaint Louis, MO 63136-6111 · (314) 953-8799

Phone(314) 953-8799

Sole ProprietorNo

Medical School CMSOtherGraduated 2002

Enumeration DateApril 17, 2012

Last NPPES UpdateOctober 27, 20254 updates tracked since enumeration

NPPES CertifiedOctober 27, 2025

✔ NPI 1851658728 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians

Taxonomy Code207RG0100X

Licenses✔ Licensed in MO · 2012032351✔ Licensed in IL · 036153515✔ Licensed in CA · A160085

Definition

An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.

11155 DUNN RD STE 309E, Saint Louis, MO 63136

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Secondary Practice Locations 2

Location 13 Saint Elizabeth BlvdO Fallon, IL 62269-1281 · Phone (618) 641-5803 · Fax (618) 607-5116

Location 24 Memorial Dr Ste 230BAlton, IL 62002-6705 · Phone (618) 463-7874

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Absolute Total Care, Ambetter from Home State Health, Ambetter Health and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Michael Ansstas M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID5092084277

PECOS Enrollment IDI20200827002746, I20230628002123

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 15

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43239

This procedure involves using a thin, flexible tube with a light and camera, known as an endoscope, to examine the esophagus, stomach, and upper part of the small intestine. Small tissue samples are taken for further examination to help diagnose various conditions.

101 services94 patients

Removal of polyps or growths of large bowel using an endoscope with mechanical snare 45385

This procedure involves using a thin, flexible tube called an endoscope to examine the large bowel. If any abnormal growths or polyps are found, a tool called a mechanical snare is used to remove them. This is a common method to prevent potential health issues.

72 services71 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232

Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.

60 services41 patients

Biopsy of large bowel using a flexible endoscope 45380

A biopsy of the large bowel using a flexible endoscope is a procedure where a thin, flexible tube with a camera is inserted through the rectum to examine the bowel. If abnormal tissue is found, a small sample is taken for further examination. This helps in diagnosing conditions like inflammation, polyps, or cancer.

49 services48 patients

Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222

Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.

36 services35 patients

Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223

Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.

34 services33 patients

Removal of stone or debris from bile or pancreatic duct using a flexible endoscope 43264

This procedure, called an endoscopic retrograde cholangiopancreatography (ERCP), involves using a flexible tube with a camera (endoscope) to locate and remove stones or debris from your bile or pancreatic duct. It's a non-surgical method to clear the ducts, enhancing your digestive health.

25 services19 patients

Balloon dilation of esophagus, stomach, and/or upper small bowel using a flexible endoscope, less than 3.0 cm 43249

This procedure involves using a flexible tube with a camera, called an endoscope, to gently expand narrowed areas in your esophagus, stomach, or upper small bowel. A small balloon is inflated, making it easier for food and liquid to pass through. It's safe and effective.

22 services21 patients

Review by radiologist of image from tube placement into bile duct using an endoscope 74328

This procedure involves a specialist, called a radiologist, examining an image taken during a tube placement into your bile duct. The tube is inserted with the help of a tool called an endoscope. This allows the doctor to check for any issues or abnormalities in your bile duct.

18 services14 patients

Insertion of stent into pancreatic or bile duct using a flexible endoscope 43274

This procedure involves the placement of a tiny tube, known as a stent, into your pancreatic or bile duct. A flexible endoscope, a long, thin instrument with a light and camera, is used. It aids in relieving blockages and improving flow in these ducts.

16 services12 patients

Diagnostic exam of large bowel using a flexible endoscope 45378

This procedure, known as a colonoscopy, involves using a flexible tube with a light and camera to examine the large intestine. It helps detect any abnormalities such as polyps or inflammation. It's a standard procedure to ensure gut health.

16 services15 patients

Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 99231

Follow-up hospital inpatient care is a daily service where a healthcare professional checks on your health progress during your hospital stay. Each session typically lasts 15 minutes, involving updates on your condition and adjustments to your treatment plan, if necessary.

16 services15 patients

Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43235

This procedure, known as an upper endoscopy, involves inserting a thin, flexible tube with a camera down the throat to examine the esophagus, stomach, and upper small bowel. It helps diagnose conditions like ulcers or inflammation.

13 services12 patients

Injection beneath lining of large bowel using a flexible endoscope 45381

This procedure involves a flexible tube, called an endoscope, being inserted into the large bowel. A small needle is then passed through the tube to inject medication under the bowel lining. This is typically done to treat inflammation or bleeding.

13 services13 patients

Colorectal cancer screening; colonoscopy on individual at high risk G0105

Colorectal cancer screening, specifically a colonoscopy, is a preventive measure for those at high risk. A thin, flexible tube with a camera inspects the colon to spot any abnormal growths. This test helps detect potential issues early, enhancing the effectiveness of treatment.

13 services13 patients

Hospital Affiliations CMS Care Compare 3

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Archbold Memorial

Acute Care Hospitals · Thomasville, GA

4/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number110038

Location915 Gordon Avenue & Mimosa DriveThomasville, GA 31792 · Thomas County

Emergency services Birthing friendly

Memorial Hospital

Acute Care Hospitals · Belleville, IL

4/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number140185

Location4500 Memorial DriveBelleville, IL 62226 · St. Clair County

Emergency services Birthing friendly

Hshs St Elizabeth's Hospital

Acute Care Hospitals · O Fallon, IL

4/5 CMS rating

OwnershipVoluntary non-profit - Church

CMS Certification Number140187

LocationOne St Elizabeth BoulevardO Fallon, IL 62269 · St. Clair County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 63136 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$128.28 typical visit price

range $55.65 – $169.38

Typical copayment $32.07 (range $13.91 – $42.34)

Most-billed visit code 99204

Established Patient

$98.37 typical visit price

range $17.76 – $137.92

Typical copayment $24.59 (range $4.44 – $34.48)

Most-billed visit code 99214

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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Other Providers at the Same Location NPPES 5

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

FOLAYEMI OLUBUSAYO GANIYU NP

Nurse Practitioner