The most common surgery in the United States depends on how you count. If you include outpatient procedures, cataract surgery takes the top spot by a wide margin, with roughly 3.8 million performed each year. If you look only at surgeries requiring a hospital stay, Cesarean sections rank first at nearly 1.17 million per year, followed by knee replacements and hip replacements. In total, U.S. hospitals performed over 14.3 million operating room procedures during inpatient stays alone in 2018.
Cataract Surgery Leads Overall Volume
Cataract surgery is the single most frequently performed surgical procedure in the country. At approximately 3.8 million operations per year, it dwarfs every other surgery by volume. Most cataract procedures take place in outpatient surgery centers rather than hospitals, which is why they don’t appear in inpatient rankings. The procedure itself typically takes under 30 minutes, and most people return to normal activities within a few days.
C-Sections Top the Inpatient List
Among surgeries that involve a hospital stay, Cesarean delivery is the clear leader. CDC data from 2023 counted 1,161,896 C-sections, representing 32.3% of all births in the United States. That means roughly one in three babies is delivered surgically. C-sections accounted for 8.1% of all inpatient operating room procedures, more than any other single surgery.
Recovery from a C-section typically takes six to eight weeks. Because it involves cutting through the abdominal wall and uterus, it carries a longer healing period than vaginal delivery and usually means a two- to four-day hospital stay.
Top 10 Inpatient Surgeries by Volume
Based on AHRQ data from 2018, here are the most frequently performed operating room procedures during hospital stays:
- Cesarean section: 1,167,700
- Knee replacement: 715,200
- Hip replacement: 599,500
- Heart stent placement (coronary intervention): 481,800
- Spinal fusion: 455,500
- Gallbladder removal: 335,200
- Broken femur repair: 307,300
- Partial colon removal: 298,600
- Spinal disc removal: 285,600
- Appendectomy: 190,000
This list only captures procedures performed during hospital admissions. Many gallbladder removals, appendectomies, and other operations now happen in outpatient settings. The share of surgeries performed on an outpatient basis grew from 37.8% in 2005 to 48.2% in 2018, meaning the inpatient numbers undercount total surgical volume for many procedures.
Joint Replacements Are Growing Fast
Knee and hip replacements together account for more than 1.3 million inpatient surgeries per year, making orthopedic procedures the dominant category outside of obstetrics. These numbers are projected to climb sharply as the population ages. Researchers estimate that by 2030, annual knee replacements could nearly triple compared to 2014 levels, and hip replacements could more than double.
The average cost of a knee or hip replacement was about $35,263 nationally in 2018, though prices varied enormously by location. In the Baltimore area, the average was around $25,000. In New York City, it was nearly $57,000 for the same procedure. Recovery typically takes three to six months before you’re back to full activity, though most people are walking with assistance within a day or two of surgery.
Spinal Surgery Is Increasingly Common
Spinal fusion and disc removal together accounted for more than 740,000 inpatient procedures in 2018. Lumbar fusion alone nearly doubled in volume between 2002 and 2023, rising from about 149,000 to over 273,000 annual procedures. The most common reason for spinal fusion is a condition called degenerative spondylolisthesis, where one vertebra slips forward over the one below it. Fusions for adult scoliosis and spinal stenosis have also surged, increasing by more than 270% and 218% respectively over two decades.
Gallbladder Removal and Appendectomy
Gallbladder removal is one of the most common abdominal surgeries, with over 750,000 performed each year across all settings. The vast majority are now done laparoscopically, through a few small incisions, which means shorter hospital stays and faster recovery compared to open surgery. The inpatient count of 335,200 represents only those cases requiring overnight hospitalization; many patients go home the same day. The average cost of an inpatient gallbladder removal reached $28,233 in 2018, nearly double what it was a decade earlier.
Appendectomy ranks 19th among inpatient surgeries at about 190,000 per year, though additional cases are handled in outpatient settings. Unlike most surgeries on this list, appendectomies are almost always emergencies rather than planned procedures. The average inpatient cost was $23,385 in 2018.
Heart Procedures Remain in the Top Five
Percutaneous coronary intervention, the procedure where a small balloon or stent opens a blocked artery in the heart, accounted for nearly 482,000 inpatient cases in 2018. Coronary artery bypass graft surgery, a more invasive operation that reroutes blood flow around blocked arteries, added another 201,600 procedures. Together, these two heart surgeries represent a significant share of operating room volume and reflect the continued burden of heart disease as the leading cause of death in the U.S.