Deignan, 30, returned from maternity leave in April, starting a two-year contract with Trek-Segafredo after giving birth to baby Orla in September last year.
The 2015 world champion has told Cycling News the plan was to give herself a shot at a second world title, on home soil in Yorkshire in September, and the chance of a gold medal in the Tokyo Olympics, before calling it a day.
“That’s been the plan,” Deignan said. “I’m open-minded to the fact that we are a a year and a half out, and that will come around quickly. Perhaps I’ve prematurely set the date. But yes, that is the plan. Of course, it’s not 100 per cent, and things could change, but for the moment that’s the plan.”
Deignan said she made the decision while she was pregnant, with the Olympics the biggest prize on her mind at the time.
“The biggest motivation for returning was to try and become the Olympic champion,” she said.
“There’s another four-year cycle after Tokyo to get to the next Olympic Games, and I think that would be too much.”
Though Deignan admitted the retirement date is not set in stone, she said it had been useful as a motivating tool.
“What’s got me through some of the times that have gotten hard with juggling everything, is that I have this two-year window to give it absolutely everything,” she added.
“I find that really motivating, rather than it be an on-going thing. I find it motivating that I’ve given myself a finish line.
“There’s definitely (pressure), but I thrive under pressure,” she added.