for Family Reunion
German law allows the reunification of spouses and minor children.
Spouses generally have the right to immigrate, if the other spouse has a legal residence, does not need social welfare and can provide for enough housing space. For spouses of a German citizen these requirements are not obligatory. Foreign spouses have to proof basic german language skills of level “A1” with a certificat of “Goethe Institut”.
A foreigners child, unmarried and below the age of 16 of a has the right to immigrate, if either both parents or the parent possessing custody posses a residence permit. Between the ages of 16 and 18, reunification is only possible if it takes place together with one parent or if the child has German language skills at the C1 level.
Children of German citizens living abroad basically have the right to immigrate as long as they are under age.
Unfortunately, the law hardly permits family reunification of parents or grandparents with adult (German) children living in Germany.
If you wish to join an EU citizen living in Germany, the more generous EU law applies first. However, if you wish to join a German national, EU law does not apply. This puts German nationals in a worse position than EU citizens, as intended by the legislator. If you hold German citizenship family reunification to another EU country may be an option.