Dr. John Mark Leib , DMD
Dentist • O Fallon, IL
741 W State St, Suite 3
O Fallon, IL 622691971
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
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NPI assigned on December 12, 2006; this date does not establish years in practice.
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Published CMS data list 77 Medicare Part D prescriptions, including refills, in 2022.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2022. Published rows only; this is not a quality measure.
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Published Part D records, 2022:
- Chlorhexidine Gluconate — 33 prescription fills, including refills.
- Amoxicillin — 25 prescription fills, including refills.
- Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) — 19 prescription fills, including refills.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2022. Drug names come from pharmacy claims. Listing a drug here is not an endorsement or a recommendation.
See the full table · Guide: How to read Medicare Part D prescriber data
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Medicare Part D prescriptions went from 47 in 2018 to 77 in 2022.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2018–2022.
Practice Location & Contact Primary Location
741 W State St
Suite 3
O Fallon, IL 622691971
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Dentist: NPPES taxonomy is a reported classification, not proof of board certification.
30-day fills
77 standardized 30-day fills in 2022
CMS converts prescriptions to 30-day supplies so they can be compared. A 90-day prescription counts as about three 30-day fills.
What this does not show: 30-day fills
It is not a count of patients and not a measure of quality.
Part D drug cost
$307 in 2022
The total cost of these prescriptions in 2022, paid by Medicare drug plans, patients and other payers together.
It shows the total spending on drugs this clinician prescribed, not what any one patient paid.
What this does not show: Part D drug cost
A higher cost often reflects the type of medicines a specialty uses. It is not your out-of-pocket cost and not a measure of quality.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2022.
Industry payments (Open Payments)
Fewer than 11 payment records totaling $13.91 in 2020
Drug and medical device companies must report certain payments to doctors and some other clinicians to CMS, such as meals, travel, speaking fees or research funding.
It shows reported financial ties between this clinician and companies. You can ask your clinician about them.
These records are submitted by drug and medical device companies, and a reported payment does not necessarily mean the financial relationship is improper.
General: payments not tied to research, such as meals, travel, consulting or speaking fees.
A reported payment does not necessarily mean the financial relationship is improper. Research payments can go to a hospital or university for a study the clinician leads, not to the clinician personally. Clinicians can dispute records with the company that reported them.
Source: CMS Open Payments, program year 2020.
NPI first issued
2006
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians; Medicare.gov, “Does your provider accept Medicare as full payment?”
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Compared with the same specialty in O Fallon and Illinois
Billing and prescribing volume is not a quality rating.
Medicare Part D
Comparisons use 2024 data. The latest CMS data for Dr. Leib are from 2022.
11 active clinicians are listed under Dentist with a practice address in O Fallon, IL (4,524 in Illinois).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in O Fallon
0% of these 11 clinicians have the CMS telehealth indicator.
0% of these 11 clinicians are listed by CMS as accepting Medicare assignment.
CMS data by year
Changes may reflect reporting, coverage or privacy limits, not changes in care quality.
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Medicare Part D prescriptions
Medicare Part D prescriptions increased 64% from 47 in 2018 to 77 in 2022.
- 2018: 47
- 2019: 101
- 2020: 126
- 2021: 197
- 2022: 77
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30-day fills
30-day fills increased 64% from 47 in 2018 to 77 in 2022.
- 2018: 47
- 2019: 101
- 2020: 126
- 2021: 197
- 2022: 77
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Part D drug cost
Part D drug cost went from $178 in 2018 to $307 in 2022.
- 2018: $178
- 2019: $428
- 2020: $453
- 2021: $753
- 2022: $307
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Industry payments (Open Payments)
CMS data for industry payments (Open Payments) are available for 2020 only.
Sources: CMS Medicare Part D Prescribers (2022), CMS Open Payments (2020), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo · Report an error.
Pharma & Medical Device Financial Disclosures
Payments and other transfers of value that drug and medical device companies reported to CMS Open Payments
Program year 2020 (payments made January 1 – December 31, 2020): fewer than 11 records totaling $13.91.
| Manufacturer | Payment Nature | Product | Type | Amount ($) |
|---|---|---|---|---|
| Zimmer Biomet Holdings, Inc. |
Food and Beverage
In-kind items and services
|
Puros | General | $13.91 |
Source: CMS Open Payments, program year 2020, released June 30, 2026.
Medicare Part D Prescribing Profile & Medications
Medicare Part D prescriptions filled, including refills, in 2022.
| Brand Name | Generic Name | Prescriptions | Day Supply | Total Cost | Patients |
|---|---|---|---|---|---|
| Chlorhexidine Gluconate | Chlorhexidine Gluconate | 33 | 489 | $169.23 | 31 |
| Amoxicillin | Amoxicillin | 25 | 169 | $95.24 | 22 |
| Hydrocodone-Acetaminophen | Hydrocodone/Acetaminophen | 19 | 25 | $42.10 | 17 |
Source: CMS Part D by Provider and Drug, 2022; rows below 11 claims omitted by CMS; volume isn’t quality. Privacy limits
Specialties & License Numbers Reported to NPPES
NUCC Taxonomy Code: 122300000X
A dentist is a person qualified by a doctorate in dental surgery (D.D.S.) or dental medicine (D.M.D.), licensed by the state to practice dentistry, and practicing within the scope of that license. There is no difference between the two degrees: dentists who have a DMD or DDS have the same education. Universities have the prerogative to determine what degree is awarded. Both degrees use the same curriculum requirements set by the American Dental Association's Commission on Dental Accreditation. Generally, three or more years of undergraduate education plus four years of dental school is required to graduate and become a general dentist. State licensing boards accept either degree as equivalent, and both degrees allow licensed individuals to practice the same scope of general dentistry. Additional post-graduate training is required to become a dental specialist.
NUCC Taxonomy Code: 1223S0112X
The specialty of dentistry which includes the diagnosis, surgical and adjunctive treatment of diseases, injuries and defects involving both the functional and esthetic aspects of the hard and soft tissues of the oral and maxillofacial region.
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Dentist - General Practice
Doctor of Dental Medicine
Dentist - General Practice
Doctor of Dental Medicine
Dentist
Doctor of Dental Medicine
Dentist - General Practice
Doctor of Dental Medicine
Career & Practice History
NPI enumerated December 12, 2006.
No changes to the name, practice address, taxonomy or NPI status in this record have been observed in the monthly NPPES data files from January 2017 to August 2026.
NPI Administrative Meta
Other Dentists in O Fallon
- Dr. Brittany Gilbreth, DMD
- Dr. Alex Schillinger, DMD
- Dr. Amanda Littlefield, DMD
- Dr. Sarah Thompson, DMD
- Dr. Roxanne Winebaugh, DMD
- Dr. Brian Sneath, DMD
Mailing Address
741 W State St, Suite 3
O Fallon, IL 622691971
Phone: 6186281800