Tokyo shot put silver medallist Saunders banned for 'whereabouts' failure
"The accumulation of three whereabouts failures within a 12-month period constitutes a rule violation under the USADA Protocol for Olympic and Paralympic Movement Testing...and the World Athletics Anti-Doping Rules," USADA said in a statement on Wednesday.
"Saunders's 18-month period of ineligibility began on Aug. 15, 2022, the date of her third whereabouts failure."
The American's competitive results from that date have also been disqualified.
She will miss the USA Outdoor Track and Field Championships in July as well as the World Championships in Budapest in August, but will be eligible to compete at next year's Paris Olympics.
The 26-year-old, who finished behind China's Gong Lijiao in Tokyo, responded to the suspension in a post on Twitter, saying, "as a veteran I definitely should've done better and I take full responsibility for my actions.
"I didn't fail a test for any substance and was tested again after each of my missed test. I've always been an advocate of clean sport"
Saunders was a fan favourite during the Tokyo Games where she sported green and purple hair and a grinning 'Joker' mask.