Questão jurídica principal
Whether the complaint against the 2015-12-28 decision on EL from 2016-01-01 was admissible without prior opposition proceedings.
Decisão extraída
It was not admissible; the insured had to first complete the opposition procedure before the cantonal court could hear the matter.
Fundamentação extraída
Under ATSG and ELG, opposition is mandatory unless a statutory exception exists. No exception applied here, and a direct appeal could not replace the required administrative review.