As reported on the UEFA official website, UEFA Champions League will change it’s format starting 2018, that means in essence that Serie A will have 4 teams qualified directly into the UCL Group Stages with no qualifying rounds, here are the details:

“The format for the UEFA Champions League and UEFA Europa League for 2018/19, 2019/20 and 2020/21 have been confirmed, with no changes to the competitions system but a new procedure for entries.

Following an extensive consultative process involving all European football stakeholders, UEFA proposed amendments which have been approved by the UEFA Executive Committee, upon recommendations of the UEFA Club Competitions Committee and the European Club Association Board.

Changes

The UEFA Europa League winners will automatically qualify for the UEFA Champions League group stage (currently they can potentially take part in a play-off round).
The top four clubs from the four top-ranked national associations will now qualify automatically for the group stage of the UEFA Champions League.
The full details of the access list for both competitions will be finalised by the end of the year.

A new system for the club coefficients: clubs will be judged on their own records (deletion of the country share for individual club coefficient unless that coefficient is lower than 20% of the association’s coefficient).
Historical success in the competition will also be acknowledged in coefficient calculation (points for previous European titles with a weighted system for UEFA Champions League and UEFA Europa League titles)
Financial distribution to clubs will be increased significantly for both competitions.
A new four-pillar financial distribution system (starting fee, performance in the competition, individual club coefficient and market pool) will see sporting performances better rewarded, while market pool share will decrease.”