v3.26.1
Cover - shares
3 Months Ended
Mar. 31, 2026
May 08, 2026
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Entity File Number 001-39264  
Entity Registrant Name KEROS THERAPEUTICS, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 81-1173868  
Entity Address, Address Line One 1050 Waltham Street,  
Entity Address, Address Line Two Suite 302  
Entity Address, City or Town Lexington,  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02421  
City Area Code 617  
Local Phone Number 314-6297  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding (in shares)   19,791,837
Amendment Flag false  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Current Fiscal Year End Date --12-31  
Entity Central Index Key 0001664710  
Common stock    
Title of 12(b) Security Common Stock, $0.0001 par value per share  
Trading Symbol KROS  
Security Exchange Name NASDAQ  
Preferred Stock    
No trading symbol true