Join Teams work meetings from Microsoft Teams (free) and vice versa

Microsoft Teams (Free) users can currently join Teams for work (or school) meetings only as guests, which requires them to use a browser and results in a sub-optimal experience. The new feature rolling out will allow these users to join Teams for work (or school) meetings in one click, without being redirected to the browser or asked to fill in their name/surname. They will also be able to continue collaborating with the meeting organizer and other participants via meeting chat after the meeting.  The feature will work in the opposite way as well, so Teams for work (or school) will just as easily be able to join meetings hosted by a Teams Free user with one click. This is associated with Roadmap ID: 167326

Users of classic Teams will be moved to New Teams soon.

Microsoft Teams has announced that it will automatically upgrade classic Teams users to new Teams after March 31, 2024. Though the upgrade will not apply to Virtualized Desktop Infrastructure (VDI) users, be aware that classic Teams on VDI support will end on June 30th 2024 as well as for the regular desktop. 

If you are a classic Teams user, you will at first see banner messages encouraging you to move to the new client. If you postpone the upgrade, you will have to do the upgrade on June 30th 2024 

If you are an admin and want to control the process, take a look at the following article on how to use policies in Teams Admin center.