Background: Antibodies against CGRP or its receptor (eptinezumab, erenumab, fremanezumab, galcanezumab, from here on: “CGRP(R) antibodies”) are modern migraine preventives. German statutory health insurance covers CGRP(R) antibodies only for patients refractory to other preventive therapies. Thus, the effect of this regulation on patient selection was investigated, as well as the effect of a change of insurance coverage for erenumab in October 2022. Methods: In total, 759 patients with CGRP(R) antibody treatment were compared with 961 patients prescribed nonspecific oral migraine preventive medicines (amitriptyline, betablocker, flunarizine, topiramate) from the DMKG Headache Registry. Results: Patients with CGRP(R) antibodies had more prior preventive therapies that were insufficiently effective or tolerated compared to patients prescribed nonspecific oral preventive medicines (p < 0.001). Moreover, they had longer disease duration (p < 0.001), more often suffered from chronic migraine (p = 0.002), had more severe headache days (p = 0.004) and acute medication days (p = 0.04), lower quality of life (p < 0.05), more comorbidities (p = 0.001), and fewer of them were working (p < 0.001). After change of insurance coverage, treatment with erenumab shifted towards less refractory patients (p < 0.001) with shorter disease duration (p < 0.001), who were less severely affected compared to patients with other CGRP(R) antibodies (e.g., headache days p = 0.01; disability p = 0.005). Conclusion: CGRP(R) antibodies are prescribed for to patients affected by exceedingly severe migraine. Insurance coverage has a significant effect on use of medicines for migraine prevention.