Cover - shares	9 Months Ended
	Sep. 30, 2021	Nov. 08, 2021
Cover [Abstract]
Entity Registrant Name	F&M BANK CORP
Entity Central Index Key	0000740806
Document Type	10-Q
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Document Period End Date	Sep. 30, 2021
Entity Filer Category	Non-accelerated Filer
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2021
Entity Common Stock Shares Outstanding		3,391,197
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	000-13273
Entity Incorporation State Country Code	VA
Entity Tax Identification Number	54-1280811
Entity Address Address Line 1	P. O. Box 1111
Entity Address City Or Town	Timberville
Entity Address State Or Province	VA
Entity Address Postal Zip Code	22853
City Area Code	540
Local Phone Number	896-8941
Entity Interactive Data Current	Yes