Ceramic thermal barrier coatings (TBC) on internally cooled metallic turbine blades give a potential for increasing the turbine gas inlet temperatures in a range of 50–150°C. Since, at higher gas inlet temperatures the remaining lifetime of the blade after failure of the TBC is extremely short, reliable lifetime prognosis for TBCs in service is required. A lifetime assessment concept is presented which is based on realistic thermal and mechanical fatigue (TMF) testing. To achieve short testing times with the TMF test rig kinetic damages, depending on the time at high temperature, are imposed separately so that a TMF cycle lasts about 1% of real service cycles. Substrate materials failed in TMF tests due to fatigue cracks. The fatigue load entailing failure of the substrate at the proposed design life determines the maximal cyclic strain of the ceramic TBC and was therefore chosen for TMF tests on TBC-coated specimens. TBCs in ‘as coated’ condition survived the required load alternations without any cracks, which implies that the premature failure of TBCs in service is due to interacting kinetic damage mechanisms.