The 47-year-old actress said in a video Sunday that she tested positive for COVID-19.
"I'm so sad that I won't be able to be at The Music Man for a little bit, but my incredible understudies Audrey Cardwell and will be holding down the fort as Marion Paroo with Mr. Hugh Jackman," Foster said.
"I just send all my love to everyone at the Winter Garden, and to all of you -- stay healthy, stay safe, and see you soon," she added.
The Music Man official Twitter account said Foster will resume performances July 6.
Foster and her co-star Hugh Jackman previously tested positive for COVID-19 in December during The Music Man previews. Jackman tested positive again this month and returned to the show June 22.
The Broadway League announced last week that it will adopt a "mask optional" policy for audience members at Broadway theaters beginning in July.
The organization said masking protocols for August and beyond will be evaluated on a monthly basis, with an announcement to be made in mid-July.