Pelosi tested positive for COVID-19, it was announced Thursday.
The announcement came a day after Pelosi, 82, appeared unmasked at an event with President Joe Biden.
She was reportedly not having any symptoms and will quarantine.
"The Speaker is fully vaccinated and boosted and is thankful for the robust protection the vaccine has provided," her spokesman Drew Hammill said Thursday.
Hammill also said an upcoming congressional trip to Asia will be postponed.
Pelosi is second in line to the presidency after the vice president.
Some information in this report comes from The Associated Press.