American
AAdvantage status is earned on Loyalty Points in a qualification year that runs March through February: one point per base mile from flying, plus points from AAdvantage cards and partners. American is a oneworld founder, so Platinum is oneworld Sapphire and Platinum Pro and above are Emerald. Confirm current thresholds on aa.com.
6 rungs, from the bottom up.
2 lounge programs in the directory.
Qualification thresholds are the published ones as last checked and change most years; confirm the current numbers with American. Alliance equivalences and the lounge rules that follow from them move far more slowly.