Tier 0:
Gear Available: General gear; Plaque Gear, Planar (Inscribed Source Stone (ISS)) Gear, Crafted Gear
12 x 5-man Expert Dungeons
6 x 5-10-man Expert Rifts
1 x Solo Chronicle
3 x 2-man Chronicle
Crafted Gear and Rune enchants
Epic Planar Gear from vendor in Meridian or Sanctum using ISS currency
Edit: would also include pvp gear as viable healing and dps spec gear
Tier 1:
Gear Available: General Gear, General Raid Gear, Mark of Ascension (Marks/MOA) Gear, Relic Gear (from last bosses of the 20-man raids)
2x 5-man Master Mode Dungeons (Master Mode Darkening Deeps (MDD) and Master Mode Caduceus Rise (MCR)
6x Tier 1 10-20man Raid Rifts
20-man Greenscale's Blight (GSB)
20-man River of Souls (ROS)
10-man Gilded Prophecy (GP)
10-man Drowned Halls (DH)
Tier 2:
Gear Available: General Gear, General Raid Gear, Greater Mark of Ascension Gear (GMOA/HK Gear), Hexed Gear (upgrades of the HK Gear), Relic Gear (from Akylios, the final boss of the 20-man HK raid)
10-man Rise of the Pheonix (RotP)
20-man Hammerknell Fortress (HK)
2x Tier 2 Raid Rifts (Fire and Earth)
Tier 3:
Upcoming, coming out in April;
20-man Infernal Dawn (ID)