For peak summer travel, fly nonstop from Atlanta to Los Angeles for $152 roundtrip on Frontier using promo code FLYLATER.
I found seats on FlyFrontier.com, using promo code FLYLATER, departing Atlanta ATL on Tuesday, July 31, returning from Los Angeles LAX on Tuesday, August 7.
The FLYLATER promo code will discount nonstop domestic travel on Tuesdays and Wednesdays, from July 4 through August 8, and it expires at 11:59 pm ET, on Sunday, June 3. Peak summer travel is usually excluded from promo code sales, so this could be a great opportunity to save on summer travel if you're able to fly mid-week. There is a large list of excluded routes.
Frontier also has another promo code for nonstop domestic travel on Mondays, Tuesdays, Wednesdays, Thursdays, and Saturdays, through June 20. The promo code FLYNOW also has some excluded routes and also expires on June 3. Many Frontier routes are only operated a few days a week so you may have to adjust your travel dates to find flights. Promo code fares are only available by entering the promo code on FlyFrontier.com.
Keep in mind that Frontier's fares only include one small personal item. Checked bag fees start at $30 each way for summer travel. Larger carry-on bag fees start at $35 each way. Adding a bag to this fare brings the total to $212 - $222 roundtrip, which is still an excellent price for peak summer travel.
Need a room in LA? Here's what's available for the above dates on Hotelwatchdog.