Her diagnosis brings the total to nine of those close to the president to contract the virus.
McEnany said in a statement that her “close contacts” did not include members of the press. She spoke with reporters outside the White House on Sunday while not wearing a mask. She said she is experiencing no symptoms.
"After testing negative consistently, including every day since Thursday, I tested positive for Covid-19 on Monday morning while experiencing no symptoms," McEnany wrote. "No reporters producers, or members of the press are listed as close contacts by the White House Medical Unit."
McEnany added that she "definitively had no knowledge" that fellow top White House official, Hope Hicks, had tested positive for the virus before McEnany held a press briefing on Thursday.
A senior White House official told NBC News that McEnany was pulled from Trump's trip to New Jersey on Thursday but was not told why.
"With my recent positive test, I will bring the quarantine process and will continue working on behalf of the American people remotely," she said.
Responding to photos showing a maskless McEnany briefing the press Sunday, Ben Williamson, a deputy assistant to the president tweeted that she "briefly removed her mask at the mic to answer questions, was there for two questions and only 58 seconds (would not constitute 'sustained contact' per the CDC), and was socially distanced from reporters in the area."
White House Correspondents' Association President Zeke Miller said in a statement the organization is "not aware of additional cases among White House journalists, though we know some are awaiting test results."
"We strongly encourage our members to continue following CDC guidance on mask-wearing and distancing — especially when at the White House — and urge journalists to seek testing if they were potentially exposed," he said.
Others, like first lady Melania Trump, former New Jersey Gov. Chris Christie, who helped prepare Trump for last week's presidential debate, and several Republican senators are among those that have announced positive tests for the virus in the days after Hicks' diagnosis was first made public.
McEnany's positive test following a series of negative results may serve as a warning to others who have been in close proximity with the president or others who have become infected but have yet to test positive themselves.
On Wednesday, Vice President Mike Pence is slated to face Sen. Kamala Harris, D-Calif., in the vice presidential debate. Pence has so far tested negative for the virus and Democratic presidential nominee Joe Biden, who shared a debate stage with Trump last week, tested negative on Sunday, his campaign announced.
This article originally appeared on NBCNews.com.