The Bundesliga is to see attendances slashed as part of a response to rising COVID-19 cases, and the spread of the Omicron variant.
Germany's federal government and state officials decided on Thursday to cap attendances at 50 per cent capacity, with a maximum of 15,000.
Only vaccinated individuals will be allowed, and they must all wear masks and adhere to social distancing guidelines.
The move is part of a wider initiative to tackle the virus by Germany authorities.
Only fully vaccinated - or those recovered from coronavirus - will be allowed inside shops, restaurants, museums, movie theatres.
Indoor sporting venues will see attendances of no more than 5,000.
The Bundestag is to vote on whether or not to make vaccines mandatory in early 2022.
Outgoing Chancellor Angela Merkel said on Thursday, "The situation is very serious. The number of infections has stabilised but on a far too high a level."
While Chancellor-designate Olaf Scholz added that vaccines are "how we get out of this crisis" and "if we had a higher vaccination rate, we wouldn't be discussing this now."
Fewer than 69 per cent of Germany's population are fully vaccinated. That's impacted on the Bundesliga too, with Bayern Munich suspending the pay of any unvaccinated players missing days for COVID-related reasons.
Bundesliga boss Christian Seifert addressed the reduced attendances measure, saying, "The DFL is aware of the current difficult COVID-19 situation, especially with a view to the strain on some regional health systems.
"In this situation... effective policy strategy is required.
"A temporary restriction on the admission of fans to the stadiums is therefore basically understandable."