Top 5 Medical Laboratory Companies in the USA
Quest Diagnostics, LabCorp, and Any Lab Test Now rank among the largest medical laboratory companies in United States in 2026 by number of locations. Quest Diagnostics operates 4,642 locations, while LabCorp and Any Lab Test Now operate 3,267 and 25 locations respectively. See the full ranking of the top 5 medical laboratory companies and compare store counts across the industry.
1Quest Diagnostics
questdiagnostics.com
Complete dataset of 4,642 Quest Diagnostics store locations across the United States, including address, phone, hours and geocodes.
4,642locations
Quest Diagnostics locations map preview — 4,642 records 
2LabCorp
labcorp.com
Complete dataset of 3,267 LabCorp store locations across the United States, including address, phone, hours and geocodes.
3,267locations
LabCorp locations map preview — 3,267 records 
3Any Lab Test Now
anylabtestnow.com
Complete dataset of 25 Any Lab Test Now store locations across the United States, including address, phone, hours and geocodes.
25locations$60View — $50
Any Lab Test Now locations map preview — 25 records