v3.26.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2026
May 01, 2026
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Entity Central Index Key 0001794546  
Current Fiscal Year End Date --12-31  
Document Quarterly Report true  
Entity File Number 001-42756  
Registrant Name CARLSMED, INC.  
Document Transition Report false  
Entity Incorporation, State or Country Code DE  
Entity Address, Address Line One 1800 Aston Ave  
Entity Address, Address Line Two Suite 100  
Entity Address, City or Town Carlsbad  
Entity Address, State or Province CA  
Entity Tax Identification Number 83-1081863  
Entity Address, Postal Zip Code 92008  
City Area Code 760  
Local Phone Number 766-1923  
Title of 12(b) Security Common Stock, $0.00001 par value per share  
Trading Symbol CARL  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period true  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   27,184,933