The Study examines Grade One learners' decoding skills, and it seeks to answer the level of decoding proficiency of grade one learners in Filipino and their Mother Tongue. Descriptive non-experimental quantitative approaches were used, and quantifiable data was used in the descriptive study "Decoding Proficiency Of Grade One Learners In Frustration Level: Basis For A School-Based Beginning Reading Program." According to Gay (2006), descriptive-correlation design validates conditions. Questionnaires collect evaluation data. This study includes grade one learners from the following elementary schools in Padada District, Davao del Sur: Padada Central Elementary School, Padada South Elementary School, Paulina J. Dinglasa Elementary School, Mariano Sarona Elementary School, and Lower Katipunan Elementary School. Just Grade 1 pupils who were frustrated on the pre-test reading assessment's decoding proficiency level were studied. This study selected 211 Grade 1 pupils from a pool of 445 learners in Padada District for the 2024–2025 academic year. Sample manageability and population representation result. First-graders' decoding skills: Filipino is Satisfactory, Mother Tongue is Outstanding, Omission; Had Not Meet Expectation, Substitution; Very Satisfactory, Repetition; Insertion. Novice readers develop hierarchically ordered sub-skills that improve comprehension, according to Dole et al. (1991). Achieving these attributes makes readers experts. Since Mother Tongue is their first language, grade one students were better at decoding faults in it than Filipino.