Musk said Twitter will always post casual posters for free, but may charge businesses and other users as he tries to expand the reach of social media platforms to a wider user base.
From what you think of Musk, the world's richest man, there's no doubt that there's a lot to say.
Musk said in the tweet: "Twitter is always free for the average user, but there may be a small fee for both commercial and government users.
It's the latest hint of changes for the world's richest man after completing his acquisition of a social media platform. In a series of tweets he's made to the platform's ambitions in recent weeks, Musk suggested making some changes to Twitter, including algorithms that apply to managing what users see on the platform.
Musk said he hopes to enhance the platform with new features that make the algorithms open source to increase trust and authenticate everyone.
It is understood that Musk has provided a new business model for Twitter and supports an ad-free model.
Musk plans to complete the take-private of Twitter later this year, and he also plans to make the company public again through a public offering in the next three years.