At the start of Division 2, only four World Tiers were available. However, a recent patch has added an extension to the end-game content, World Tier 5. This is how to unlock it, and what you can do once reaching it.
World Tier 5 can be unlocked once first reaching World Tier 4, and then accumulating a Gear Score of 450.
Once reaching this point, you will need to complete the Capitol Building and Roosevelt Island Strongholds one more time, unlocking another side mission that is integral to reaching World Tier 5.
Complete the new Gatehouse Facility side mission to unlock the Tidal Basin invasion mission. Once completing this mission, you will finally reach the new World Tier 5.
Along with the joy of progression, World Tier 5 adds some little benefits to your player to incentivize reaching it.
Reaching WT5 increases the Gear Score rating from the previous cap of 450 t0 500, allowing you to beef up your player more than ever before.
3 new gear sets came with the release of World Tier 5, True Patriot, Ongoing Directive, and Hardwired. These armor sets are integral to reaching the new cap of 500 for maximum armor ability.
The game promotes building a full set by giving extra bonuses along with the regular armor effects for the more pieces of a set that you are wearing. The bonuses for all three sets are shown below:
|2||20% Skill health|
|3||20% Shock resistance|
|4||20% Skill power|
|5||All skills receive shock ability every 10 seconds.|
|6||Reduced cooldown on skills after killing with skill.|
|2||10% Increased armor damage|
|3||10% less damage from elites|
|4||10% Additional armor|
|5||Causes enemies to have one of three debuffs: deal less damage, heal allies, or lower your skill cooldown when hit. A single enemy can have all three debuffs.|
|6||Shotting enemy with all three debuffs damages other enemies in range.|
|2||20% Increased weapon handling|
|3||25% Additional burn damage|
|4||25% Additional bleed damage|
|5||Automatically pick up restock items within 40-meter radius every 30 seconds|
|6||Gain ammo for alternate weapons upon kill.|