In addition to quarantine, Germany requires a mandatory PCR test

As of 11.01.2021, upon entering the entire territory of the Federal Republic of Germany 
from a risk region / incl. Bulgaria /, together with the 10-day mandatory quarantine, 
a mandatory presentation of a negative PCR test upon arrival is introduced. 
The mandatory test can be carried out within 48 hours before entering Germany or by testing immediately upon arrival.

Mandatory quarantine can be terminated at the earliest on the 5th day, 
after an additional test for KOVID-19 is performed on site in Germany, according to the instructions 
of the local authorities.

The quarantine ordinance enters into force on January 11, 2021 and will apply to the entire territory of the country
 in accordance with the requirements of each federal province.