Career milestones

Career Milestones were Halo Waypoint's overall measure of participation and performance across all Halo games released since September 2007. While they are still visible on the Xbox 360 version, Career Milestones were removed from the web version of Waypoint on October 13, 2014, and replaced by a simple Gamerscore total.

Only Xbox 360, Windows 8, and Windows Phone 8 achievements contribute to Career milestones. Halo 2 for Windows Vista and Xbox One achievements are not supported.

Description
Milestones are reached by attaining a certain level of Halo gamerscore. When designated Halo Gamerscore levels are reached, new Milestones are earned and awarded in the Career section. Players begin at Milestone 1. As new Halo achievements are earned, players level up their career milestone. Each additional Milestone beyond level 16 requires 100 Gamerscore to unlock; earlier Milestones require fewer.

There were originally 40 milestones available at launch. It currently takes 8900 Halo Gamerscore to reach the maximum milestone 100. All those on a player's friend list are able to view the player's milestones.

Avatar Awards
Halo Spartan EVA Helmet - Make it into Career Milestone 50.

Halo: Reach Armor Unlocks
Once specific Career Levels have been met, certain Armory Items can be unlocked but only after earning certain achievements in Halo 3, Halo 3: ODST, or Halo: Reach.

Helmet
Military Police: Base - Career Level 15. Earn The Soldier We Needed You To Be achievement in Halo: Reach. Military Police: CBRN/HU/RS - Career Level 20. Earn the Pink and Deadly achievement in Halo 3: ODST. Must have Military Police: Base. Military Police: HU/RS/CNM - Career Level 25. Earn the Fear the Pink Mist achievement in Halo 3 and the A Spoonful of Blamite achievement in Halo: Reach. Must have Military Police: CBRN/HU/RS. CQB: Base - Career Level 20. Earn the Folks Need Heroes... achievement in Halo: Reach. CQB: HU/RS/CNM - Career Level 25. Earn the Campaign Complete: Heroic achievement in Halo 3: ODST. Must have CQB: Base. CQB: UA/HUL - Career Level 30. Earn the Campaign Complete: Legendary achievement in Halo 3 and the Gods Must Be Strong achievement in Halo: Reach. Must have CQB: HU/RS/CNM.

Chest
UA/Base Security [W]  - Career Level 30. Earn the Yes, Sensei achievement in Halo: Reach.