Dr. Zachary Zimmer, M.D.
Contact & Location
301-926-0200
Gaithersburg, MD 20879
Silver Spring, MD 20904
About Dr. Zimmer
Practice. Dr. Zachary Zimmer is an orthopedic surgeon practicing in Washington, District of Columbia. The latest annual CMS data records 13 shoulder replacements. That is #4 in District of Columbia for shoulder replacement. Dr. Zimmer also holds credentials in Sports Medicine.
Trend. Medicare records run from 2018 to 2024, 3 years. Volume has held between 13 and 17 procedures a year.
National context. Among 2,217 shoulder replacement surgeons tracked nationally, 13 procedures is below the national average of 29. Medicare covers part of all joint replacements, so true volume is likely higher.
Local context. Washington has 16 orthopedic surgeons in the current Medicare data. Comparing volume and procedure mix across them is one way to narrow a shortlist.
Verified Case Volume Trends (2013-Current)
| Year | Shoulder Replacement |
|---|---|
| 2013 | 0 |
| 2014 | 0 |
| 2015 | 0 |
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 15 |
| 2019 | 17 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 13 |
Verified Medicare Cases
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 29% to 37% for shoulder 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. Zimmer Compares
Procedure volume compared to the District of Columbia state average.
See the Top 25 shoulder replacement surgeons in District of Columbia
Volume Trend Analysis
Dr. Zimmer's procedure volume has been consistent across 3 years of Medicare data, ranging from 13 to 17 procedures per year. This stability suggests a well-established joint replacement practice.
Hospital Affiliations & Quality
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 Shoulder Replacement
If you are considering shoulder replacement surgery, these evidence-based guides can help you prepare and recover:
A practical checklist of questions covering experience, technique, hospital choice, and recovery expectations to discuss during your surgical consultation.
Recovery Timeline: Week-by-Week ExpectationsA detailed week-by-week guide covering pain levels, mobility milestones, physical therapy progression, and when to expect a return to daily activities.
Outpatient Joint Replacement: A Medicare GuideHow outpatient joint replacement works under Medicare, including eligibility criteria, cost differences, and what to expect with same-day discharge.
Shoulder Replacement Recovery Overview
Recovery timelines vary by patient, but here is a general overview of what to expect after shoulder replacement surgery:
Individual recovery varies based on overall health, age, and adherence to physical therapy. View full shoulder replacement recovery guide and product recommendations
Frequently Asked Questions About Dr. Zimmer
How does Dr. Zimmer's procedure volume compare to other District of Columbia surgeons?
Dr. Zimmer has performed 13 Medicare-verified joint replacement procedures. The District of Columbia average is 58 procedures per surgeon. Medicare data captures roughly one-third of all joint replacements, so total volume may be higher. Dr. Zimmer ranks #15 out of 16 orthopedic surgeons in District of Columbia.
What types of joint replacement does Dr. Zimmer perform?
Dr. Zimmer's reported Medicare volume is focused on shoulder replacement, with 13 verified procedures. Some surgeons choose to concentrate on a single joint type to build deep procedural expertise.
How experienced is Dr. Zimmer with shoulder replacement surgery?
Dr. Zimmer ranks #4 in District of Columbia for shoulder replacement with 13 Medicare-verified procedures. This high ranking among 16 state surgeons indicates significant experience with this specific procedure.
Where is Dr. Zimmer's practice located?
Dr. Zimmer's current practice address is in Gaithersburg, MD. That address is the current practice address in Dr. Zimmer's own CMS NPPES registry entry, which providers maintain themselves. The Medicare claims data used for the rankings on this page was billed from Washington, District of Columbia.
What does the Medicare data for Dr. Zimmer 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 29% to 37% for shoulder replacement, which puts Dr. Zimmer's total volume across all insurers at roughly 40 to 40 procedures against the 13 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. Zimmer's procedure volume changed over time?
Dr. Zimmer's procedure volume has been relatively stable over 3 years of Medicare data, ranging from 13 to 17 procedures per year between 2018 and 2024. Consistent volume over multiple years reflects a steady joint replacement practice.
Which hospitals is Dr. Zimmer affiliated with?
According to CMS facility affiliation data, Dr. Zimmer is affiliated with George Washington Univ Hospital, Cedar Hill Regional Medical Center.
How does Dr. Zimmer compare to other orthopedic surgeons in Washington?
Among the 16 orthopedic surgeons in Washington, Dr. Zimmer ranks #15 by total Medicare procedure volume. The highest-volume surgeon in Washington has 126 verified Medicare procedures.
What are the quality ratings for hospitals where Dr. Zimmer practices?
George Washington Univ Hospital (1 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 Washington, District of Columbia
Dr. Zimmer's 13 Medicare procedures are below the Washington average of 82. The table below compares verified procedure volumes for orthopedic surgeons practicing in Washington.
| Surgeon | Procedures | Specialties |
|---|---|---|
| Dr. Savyasachi Thakkar | 126 | Hip, Knee |
| Dr. Anthony Unger | 123 | Hip, Knee |
| Dr. Kenneth Vaz | 92 | Hip, Knee |
| Dr. Matthew Harb | 83 | Hip, Knee |
| Dr. Afamefuna Nduaguba | 68 | Hip, Knee |
| Dr. Ahamefula Onyike | 66 | 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.