Dr. Glen O'sullivan, M.D.

Specialist

16 procedures5 hospitalsMount Shasta, CAUpdated May 2026

Contact & Location

866-668-3597
Phone: 866-668-3597
Practice phone listed in the NPI registry
635 Lassen Ln
Mount Shasta, CA 96067
Current practice address per the CMS NPPES registry (self-reported to the registry, last updated November 2010). Registry checked August 2026.
NPI: 1972504652
Credentials: M.D.
Active Medicare provider (NPI verified)
21 years of practice experience
Licensed M.D.
Contact information available
Find Practice on Google Maps
National Comparison by Procedure
Hip 16 vs 36 national avg 0.4x
avg

Compared with 4,542 hip surgeons in the 2024 Medicare dataset.

Dr. O'sullivan performs more hip replacement procedures than 19% of orthopedic surgeons in California, based on 2024 Medicare claims volume.Derived from the state ranking shown on this page: #279 of 348 ranked hip surgeons in California.

About Dr. O'sullivan

Practice. Dr. Glen O'sullivan is a board-certified orthopedic surgeon practicing in Mount Shasta, California. The latest annual CMS data records 16 hip replacements. That is #279 in California for hip replacement. A Medicare provider since 2005.

Trend. Medicare records run from 2016 to 2024, 6 years. Volume rose from 12 procedures a year to 16, up 33%.

National context. Among 4,542 hip replacement surgeons tracked nationally, 16 procedures is below the national average of 36. Medicare covers part of all joint replacements, so true volume is likely higher.

Local context. Mount Shasta has 2 orthopedic surgeons in the current Medicare data. Comparing volume and procedure mix across them is one way to narrow a shortlist. Dr. O'sullivan also holds hospital privileges in CA and OR, a practice that extends beyond California.

Verified Medicare Cases

Hip Replacement
16 verified cases
#279 in California
Estimated 2024 total: 50 – 60 procedures (all insurers)
Medicare fee-for-service share of national volume in 2024: 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 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. O'sullivan Compares

Procedure volume compared to the California state average.

Hip Below Avg
16 Avg: 41
Dr. O'sullivan California Average

Volume Trend Analysis

Dr. O'sullivan's Medicare-recorded procedure volume has trended upward over 6 years, increasing 33% from 12 procedures in 2016 to 16 in the most recent data.

Years of Data 6
2024 Volume 16
Peak Volume 16 (2024)
Trend Growing

Hospital Affiliations & Quality

H
Mercy Medical Center Mt Shasta
3/5
Mount Shasta, CA
Low case volume
H
Asante Ashland Community Hospital
Ashland, OR
Low case volume
H
Fairchild Medical Center
1/5
Yreka, CA
Similar to national avg
H
Asante Rogue Regional Medical Center
4/5
Medford, OR
Low case volume
H
Asante Three Rivers Medical Center
5/5
Grants Pass, OR
Low case volume

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 Hip Replacement

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

Hip Replacement Recovery Overview

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

Week 1-2 Walking with assistive device (walker or cane). Gentle range-of-motion exercises begin. Most patients can manage basic self-care.
Week 3-6 Transition to walking independently. Resume driving short distances. Physical therapy focuses on strength and balance.
Week 7-12 Return to most daily activities and light exercise. Stair climbing improves. Many patients return to desk work.
Month 4-6 Full recovery for most patients. Resume recreational activities, golf, swimming, and low-impact exercise.

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

Frequently Asked Questions About Dr. O'sullivan

How does Dr. O'sullivan's procedure volume compare to other California surgeons?

Dr. O'sullivan has performed 16 Medicare-verified joint replacement procedures. The California average is 68 procedures per surgeon. Medicare data captures roughly one-third of all joint replacements, so total volume may be higher. Dr. O'sullivan ranks #504 out of 613 orthopedic surgeons in California.

What types of joint replacement does Dr. O'sullivan perform?

Dr. O'sullivan's reported Medicare volume is focused on hip replacement, with 16 verified procedures. Some surgeons choose to concentrate on a single joint type to build deep procedural expertise.

Are there other orthopedic surgeons near Dr. O'sullivan in Mount Shasta?

Yes. There are 2 orthopedic surgeons in Mount Shasta 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 California surgeons.

What does the Medicare data for Dr. O'sullivan 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 25% to 33% for hip replacement, which puts Dr. O'sullivan's total volume across all insurers at roughly 50 to 60 procedures against the 16 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. O'sullivan's procedure volume changed over time?

Yes. Dr. O'sullivan's Medicare-recorded volume has increased from 12 procedures in 2016 to 16 in the most recent data, a 33% increase over 6 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 16 procedures in 2024.

Which hospitals is Dr. O'sullivan affiliated with?

According to CMS facility affiliation data, Dr. O'sullivan is affiliated with Mercy Medical Center Mt Shasta, Asante Ashland Community Hospital, Fairchild Medical Center, Asante Rogue Regional Medical Center, Asante Three Rivers Medical Center. Dr. O'sullivan maintains hospital privileges across state lines, indicating a practice that serves patients in multiple states.

What are the quality ratings for hospitals where Dr. O'sullivan practices?

Mercy Medical Center Mt Shasta (3 out of 5 CMS stars, insufficient case volume for complication rate comparison); Asante Ashland Community Hospital (insufficient case volume for complication rate comparison); Fairchild Medical Center (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 Mount Shasta, California

Dr. O'sullivan's 16 Medicare procedures are below the Mount Shasta average of 31. The table below compares verified procedure volumes for orthopedic surgeons practicing in Mount Shasta.

SurgeonProceduresSpecialties
Dr. Todd Guthrie 45 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. Glen O'sullivan, M.D. -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/ca/dr-glen-osullivan-mount-shasta.html

Link: https://orthoprocedures.com/surgeons/ca/dr-glen-osullivan-mount-shasta.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.