#20 Shoulder
#80 Knee

Dr. Stephen Koss, MD

Orthopedic Surgery
47 procedures 1 hospital Hackettstown, NJ
Latest available Medicare data — updated April 2026
Rising Star
Knee replacement recovery kit Ice machines, mobility aids, bathroom safety — under $50 essentials
National Comparison by Procedure
Knee 28 vs 45 avg (6,720 surgeons)
Shoulder 19 vs 28 avg (2,092 surgeons)

Dr. Stephen Koss is a board-certified orthopedic surgeon practicing in Hackettstown, New Jersey. A Medicare provider since 2006, Dr. Koss has performed 28 Medicare-verified knee replacements (#80 in New Jersey) and 19 shoulder replacements, for a combined total of 47 procedures.

In New Jersey, Dr. Koss performs below average in knee (28 vs 53 avg), below average in shoulder (19 vs 28 avg).

Dr. Koss's reported Medicare volume is split between knee replacements (28 cases) and shoulder replacements (19 cases).

Hackettstown is home to 4 orthopedic surgeons in the current Medicare dataset. Patients in the Hackettstown area can compare surgeon volume and procedure specialization to find the right fit for their joint replacement needs.

Medicare records for Dr. Koss extend back to 2013, covering 11 years of data. Over that period, recorded procedure volume increased from 11 to 47 in the most recent data, a 327% increase. This sustained growth reflects an expanding joint replacement practice.

Dr. Koss's 28 knee replacement procedures is below the national average of 45 among 6,720 surgeons. Medicare data captures roughly a third of all joint replacements, so actual volume is likely higher.

Verified Medicare Cases

Knee Replacement
28 verified cases
#80 in New Jersey
Shoulder Replacement
19 verified cases
#20 in New Jersey
Estimated total: 130 – 140 procedures (all insurers)
Based on Medicare FFS representing 33–37% of national joint replacement volume
How is this estimated?

Medicare Part B fee-for-service claims represent approximately 33–37% of all joint replacements performed nationally (source: CMS data, AJRR). This range estimates the surgeon's total practice volume across all payers. The verified Medicare count above is the definitive, audited figure.

How Dr. Koss Compares

Procedure volume compared to the New Jersey state average.

Knee Below Avg
28 Avg: 53
Shoulder Below Avg
19 Avg: 28
Dr. Koss New Jersey Average

Contact & Location

Phone: 908-684-3005
108 Bilby Rd
Hackettstown, NJ 07840
NPI: 1265482897
Credentials: MD
Active Medicare provider (NPI verified)
20 years of practice experience
Licensed MD
Licensed surgical specialist
Board-certified orthopedic surgeon
Sports medicine specialist
Contact information available
Find Practice on Google Maps

Volume Trend Analysis

Dr. Koss's Medicare-recorded procedure volume has trended upward over 11 years, increasing 327% from 11 procedures in 2013 to 47 in the most recent data.

Years of Data 11
2023 Volume 47
Peak Volume 47 (2023)
Trend Growing

Hospital Affiliations & Quality

H
Morristown Medical Center
★★★★★
Morristown, NJ
Similar to national avg

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.

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. Koss

How does Dr. Koss's procedure volume compare to other New Jersey surgeons?

Dr. Koss has performed 47 Medicare-verified joint replacement procedures. The New Jersey average is 71 procedures per surgeon. Medicare data captures roughly one-third of all joint replacements, so total volume may be higher. Dr. Koss ranks #79 out of 182 orthopedic surgeons in New Jersey.

What types of joint replacement does Dr. Koss perform?

Dr. Koss's Medicare data shows procedures in knee replacement (28 cases) and shoulder replacement (19 cases).

Are there other orthopedic surgeons near Dr. Koss in Hackettstown?

Yes. There are 4 orthopedic surgeons in Hackettstown 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 New Jersey surgeons.

What does the Medicare data for Dr. Koss represent?

The procedure counts shown are based on the most recent Medicare Part B fee-for-service claims data, published by the Centers for Medicare and Medicaid Services (CMS). This captures approximately 33–37% of all joint replacements performed nationally. Dr. Koss's total practice volume — including private insurance and Medicare Advantage patients — is likely higher than the 47 procedures shown here.

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

Yes. Dr. Koss's Medicare-recorded volume has increased from 11 procedures in 2013 to 47 in the most recent data, a 327% increase over 11 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 47 procedures in 2023.

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

Yes. Dr. Koss's Medicare data shows procedures in knee replacement (28 cases), shoulder replacement (19 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.

Which hospitals is Dr. Koss affiliated with?

According to CMS facility affiliation data, Dr. Koss is affiliated with Morristown Medical Center.

How does Dr. Koss compare to other orthopedic surgeons in Hackettstown?

Among the 4 orthopedic surgeons in Hackettstown, Dr. Koss ranks #2 by total Medicare procedure volume. Dr. Koss is among the highest-volume surgeons in Hackettstown.

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

Morristown Medical Center (5 out of 5 CMS stars, hip/knee complication rate similar to national average). These are hospital-level quality metrics from CMS Hospital Compare and do not reflect individual surgeon outcomes.

Other Orthopedic Surgeons in Hackettstown, New Jersey

Dr. Koss's 47 Medicare procedures are below the Hackettstown average of 105. The table below compares verified procedure volumes for orthopedic surgeons practicing in Hackettstown.

SurgeonProceduresSpecialties
Dr. John Dundon 320 Hip, Knee
Dr. Robert Masella 41 Hip, Knee
Dr. Michael Deehan 13 Knee

Patient Reviews & Ratings

OrthoProcedures.com focuses on verified Medicare procedure data. For patient reviews, ratings, and appointment scheduling, visit these trusted platforms:

These links lead to third-party websites. OrthoProcedures.com is not affiliated with these platforms and cannot verify the accuracy of reviews.

Cite This Data

APA: OrthoProcedures. (2026). Dr. Stephen Koss, MD -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/nj/dr-stephen-koss-hackettstown.html

Link: https://orthoprocedures.com/surgeons/nj/dr-stephen-koss-hackettstown.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.