KISS expects to return to the stage for its Sept. 9 show in Irvine.
"While Paul Stanley recently tweeted that he has recovered from COVID, Gene Simmons has now tested positive and is experiencing mild symptoms," according to a statement from the band.
"The band and crew will remain at home and isolate for the next 10 days."
According to the statement, doctors have told band members they should be able to resume their tour beginning with the scheduled show at the FivePoint Amphitheatre in Irvine.
The four postponed shows are in Michigan, Ohio, Illinois and Wisconsin.
Simmons, 72, is an outspoken supporter of COVID vaccines and vaccine mandates. The band previously stated that all of its members and tour crew are fully vaccinated.
Gene Simmons talks about taking precautions during the pandemic
Celebrity Gene Simmons from KISS tells us to get over ourselves and stay home during the coronavirus