Are Turkish citizens exempt from the German language requirement for family reunification? (Dogan ruling)

No, there is no automatic exemption. This is a widespread misconception.

It stems from the Court of Justice of the European Union's Dogan ruling (C-138/13, 10 July 2014). The Court held that the German rule as it then stood breached the standstill clause of the EEC–Turkey Association Agreement. The reason was specific: missing proof of language skills led to an automatic refusal, with no room to consider the applicant's individual circumstances.

Germany addressed that objection on 1 August 2015 by adding § 30 (1) sentence 3 no. 6 to the Residence Act. The Federal Foreign Office's current Visa Handbook now states explicitly that proof of language skills may be required also from the spouse of a Turkish national covered by association law, and that the standstill clause no longer stands in the way.

What does remain — the hardship exception: if, because of the particular circumstances of the individual case, it is impossible or unreasonable for the spouse to make efforts to learn basic German before entry, the requirement does not apply. That is the lasting effect of Dogan: a refusal cannot be automatic, and each case must be assessed individually.

Whether your situation falls under that exception is a question for a lawyer.

Source: Federal Foreign Office Visa Handbook, section on spouse reunification with an association-privileged Turkish spouse

This is general information, not legal advice.