Cover Page - shares	3 Months Ended
	Mar. 31, 2020	May 27, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-35342
Entity Registrant Name	LUMOS PHARMA, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	42-1491350
Entity Address, Address Line One	4200 Marathon Blvd #200
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78756
City Area Code	512
Local Phone Number	215-2630
Title of 12(b) Security	Common Stock
Trading Symbol	LUMO
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	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		8,292,803
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001126234
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false