Dr. Mark Oyer, M.D.

Orthopedic Surgery
Ranked 10 of 251#10of 251
Knee rank in Illinois

210 procedures5 hospitalsRockford, ILUpdated May 2026

Built on public CMS Medicare data Growing Volume Top 10% Nationally

Contact & Location

815-398-9491
Phone: 815-398-9491
Practice phone listed in the NPI registry
5875 E Riverside Blvd
Rockford, IL 61114
Current practice address per the CMS NPPES registry (self-reported to the registry, last updated August 2023). Registry checked August 2026.
NPI: 1679968812
Credentials: M.D.
Active Medicare provider (NPI verified)
11 years of practice experience
Licensed M.D.
Licensed surgical specialist
Board-certified orthopedic surgeon
Contact information available
Find Practice on Google Maps
National Comparison by Procedure
Hip 80 vs 36 national avg 2.2x
avg
Knee 130 vs 45 national avg 2.9x
avg

Compared with 4,542 hip surgeons and 6,612 knee surgeons in the 2024 Medicare dataset.

Dr. Oyer performs more knee replacement procedures than 96% of orthopedic surgeons in Illinois, based on 2024 Medicare claims volume.Derived from the state ranking shown on this page: #10 of 251 ranked knee surgeons in Illinois.

About Dr. Oyer

Practice. Dr. Mark Oyer is a board-certified orthopedic surgeon practicing in Rockford, Illinois. The latest annual CMS data records 130 knee replacements and 80 hip replacements, 210 procedures in all. That is #10 in Illinois for knee replacement. A Medicare provider since 2015.

Trend. Medicare records run from 2020 to 2024, 5 years. Volume rose from 24 procedures a year to 210, up 775%.

National context. Among 6,612 knee replacement surgeons tracked nationally, 130 procedures is more than 2x the national average of 45.

Local context. Rockford has 8 orthopedic surgeons in the current Medicare data. Comparing volume and procedure mix across them is one way to narrow a shortlist.

Verified Medicare Cases

Knee Replacement
130 verified cases
#10 in Illinois
Hip Replacement
80 verified cases
#18 in Illinois
Estimated 2024 total: 710 – 890 procedures (all insurers)
Medicare fee-for-service share of national volume in 2024: 23% to 28% for knee replacement, 25% to 33% for hip replacement
How is this estimated?

Medicare Part B fee-for-service claims are one payer stream among several, and the share they represent differs by procedure. In 2024 it was 23% to 28% for knee replacement, 25% to 33% for hip replacement. Each verified count above is divided by its own procedure's range, and the results are added, to estimate total practice volume across all payers. The verified Medicare count is the definitive, audited figure; this is a range derived from published national volume projections, not a measurement, and an individual practice can sit well outside it: how these ranges are derived, and their sources.

How Dr. Oyer Compares

Procedure volume compared to the Illinois state average.

Hip Very High
80 Avg: 39
Knee Very High
130 Avg: 50
Dr. Oyer Illinois Average

Volume Trend Analysis

Dr. Oyer's Medicare-recorded procedure volume has trended upward over 5 years, increasing 775% from 24 procedures in 2020 to 210 in the most recent data.

Years of Data 5
2024 Volume 210
Peak Volume 213 (2023)
Trend Growing

Hospital Affiliations & Quality

H
Saint Anthony Medical Center
2/5
Rockford, IL
Similar to national avg
H
Cgh Medical Center
2/5
Sterling, IL
Similar to national avg
H
Uw Health
3/5
Rockford, IL
Low case volume
H
Osf Saint Katharine Medical Center
2/5
Dixon, IL
Low case volume
H
Osf Saint Paul Medical Center
Mendota, IL

Quality ratings and complication rates are hospital-level metrics from CMS Hospital Compare and do not reflect individual surgeon performance. Star ratings updated quarterly. Complication data covers a rolling 3-year period.

Patient Resources: Preparing for Knee Replacement

If you are considering knee replacement surgery, these evidence-based guides can help you prepare and recover:

Knee Replacement Recovery Overview

Recovery timelines vary by patient, but here is a general overview of what to expect after knee replacement surgery:

Week 1-2 Walking with assistive device. Knee bending exercises begin immediately. Ice therapy and elevation for swelling control.
Week 3-6 Increased range of motion (target 90 degrees). Walking longer distances. Physical therapy intensifies with strengthening exercises.
Week 7-12 Most patients walk without assistive devices. Resume driving and desk work. Continue PT for strength and flexibility.
Month 4-6 Near-full recovery. Resume most recreational activities. Some swelling and stiffness may persist but continues improving.

Individual recovery varies based on overall health, age, and adherence to physical therapy. View full knee replacement recovery guide and product recommendations

Frequently Asked Questions About Dr. Oyer

How does Dr. Oyer's procedure volume compare to other Illinois surgeons?

Dr. Oyer has performed 210 Medicare-verified joint replacement procedures. This is more than 3x the Illinois average of 69 procedures per surgeon. Dr. Oyer ranks #12 out of 316 orthopedic surgeons in Illinois.

What types of joint replacement does Dr. Oyer perform?

Dr. Oyer's Medicare data shows procedures in knee replacement (130 cases) and hip replacement (80 cases).

How experienced is Dr. Oyer with knee replacement surgery?

Dr. Oyer ranks #10 in Illinois for knee replacement with 130 Medicare-verified procedures. This high ranking among 316 state surgeons indicates significant experience with this specific procedure.

Are there other orthopedic surgeons near Dr. Oyer in Rockford?

Yes. There are 8 orthopedic surgeons in Rockford in the current Medicare dataset. Patients can compare procedure volumes and specializations to choose the surgeon who best fits their needs. Use the state page to view all Illinois surgeons.

What does the Medicare data for Dr. Oyer represent?

The procedure counts shown are based on 2024 Medicare Part B fee-for-service claims data, published by the Centers for Medicare and Medicaid Services (CMS). Medicare fee-for-service is only one payer stream, and the share of national volume it represents differs by procedure. In 2024 the share was 23% to 28% for knee replacement, 25% to 33% for hip replacement, which puts Dr. Oyer's total volume across all insurers at roughly 710 to 890 procedures against the 210 verified here. Those shares are derived from published national volume projections rather than quoted from a single publication, and they are estimates with real uncertainty. The OrthoProcedures methodology page shows the full derivation, the sources, and the limits at orthoprocedures.com/data-methodology.html.

Has Dr. Oyer's procedure volume changed over time?

Yes. Dr. Oyer's Medicare-recorded volume has increased from 24 procedures in 2020 to 210 in the most recent data, a 775% increase over 5 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 213 procedures in 2023.

Does Dr. Oyer perform more than one type of joint replacement?

Yes. Dr. Oyer's Medicare data shows procedures in knee replacement (130 cases), hip replacement (80 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.

Which hospitals is Dr. Oyer affiliated with?

According to CMS facility affiliation data, Dr. Oyer is affiliated with Saint Anthony Medical Center, Cgh Medical Center, Uw Health, Osf Saint Katharine Medical Center, Osf Saint Paul Medical Center.

How does Dr. Oyer compare to other orthopedic surgeons in Rockford?

Among the 8 orthopedic surgeons in Rockford, Dr. Oyer ranks #1 by total Medicare procedure volume. Dr. Oyer has the highest verified Medicare volume in the city.

What are the quality ratings for hospitals where Dr. Oyer practices?

Saint Anthony Medical Center (2 out of 5 CMS stars, hip/knee complication rate similar to national average); Cgh Medical Center (2 out of 5 CMS stars, hip/knee complication rate similar to national average); Uw Health (3 out of 5 CMS stars, insufficient case volume for complication rate comparison). These are hospital-level quality metrics from CMS Hospital Compare and do not reflect individual surgeon outcomes.

Other Orthopedic Surgeons in Rockford, Illinois

Dr. Oyer's 210 Medicare procedures are above the Rockford average of 99. The table below compares verified procedure volumes for orthopedic surgeons practicing in Rockford.

SurgeonProceduresSpecialties
Dr. John Bottros 173 Hip, Knee
Dr. Jeremiah Pflederer 100 Hip, Knee
Dr. Mark Barba 88 Hip, Knee
Dr. Scott Trenhaile 53 Shoulder
Dr. Mathew Legel 38 Hip, Knee
Dr. Andrew Blint 32 Hip, Knee

Patient Resources & Verification

Research reviews, verify credentials, and check official quality data through these trusted sources:

Medicare Care Compare and NPI Registry are official U.S. government sources. Google reviews reflect user-submitted feedback. OrthoProcedures.com does not verify the accuracy of third-party review content.

Cite This Data

APA: OrthoProcedures. (2026). Dr. Mark Oyer, M.D. -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/il/dr-mark-oyer-rockford.html

Link: https://orthoprocedures.com/surgeons/il/dr-mark-oyer-rockford.html

Data source: CMS Medicare Part B Provider Utilization & Payment Data. Full methodology | Open Data API

Important: Rankings are based solely on Medicare procedure volume and do not reflect quality of care, patient outcomes, or procedures covered by private insurance. This data represents approximately one-third to 40% of all joint replacement procedures nationwide. Always consult with healthcare providers to make informed decisions about your care.