ICYMI stands for "in case you missed it".

 ICYMI stands for "in case you missed it". [1]

Meaning and Usage

Definition: It is a popular internet initialism used to draw attention to a news piece, article, update, or post that was shared previously or might have been overlooked. [1, 2, 3]
Where it is used: Commonly found in social media posts (like X/Twitter), promotional emails, newsletters, and digital journalism headlines. [1, 2, 3, 4]
Tone: Informal, friendly, and helpful rather than repetitive. [1, 2]

If you'd like, let me know if you need help writing a post or email using ICYMI, or if you are looking for information on another internet abbreviation.