The requirement for a negative test is also extended to immunised persons entering the country from an area dominated by a more aggressive variant, which is not the predominant one in Germany.
In addition, non-immunised people arriving from high-risk areas - including Spain and the Netherlands - will have to complete a 10-day quarantine, which can be reduced by submitting a negative test five days after arrival in Germany.
Travellers arriving from areas where more aggressive variants of the virus are present - currently Brazil and Uruguay - will have to remain in quarantine for 14 days, regardless of whether they are immunised or not, with no option to shorten the isolation.
Unimmunised children under 12 years of age can be exempted from quarantine five days after arrival in the country from a high-risk region, without the need for retesting.
In case of a previous stay in an area at risk due to the presence of variants, the isolation period for minors - immunised or not - will also be 14 days.
Meanwhile, the cumulative seven-day incidence in Germany has increased from four weeks ago and stands at 17.5 new infections per 100,000 inhabitants (16.9 on Saturday and 13.8 last Sunday).
Health authorities have reported 2,097 new infections and one death in the past 24 hours, compared with 1,387 infections and four deaths a week ago, while active cases stand at around 25,100.
As of 30 July, 61.6 percent of the population had been vaccinated, 52 percent of which had been fully vaccinated.