The importance of being able to read for children’s future is beyond doubt. In Indonesia, on the one hand, a standardized linguistically-based test is needed to identify reading milestones and the Tes Membaca Satu Menit (TMSM) is a pioneer in that respect. In other countries, such tests have existed for a long time, such as the Een Minuut Lesetest in the Netherlands. On the other hand, the Early Grade Reading Assessment had existed and been used before by education authorities and practitioners, although it needs to be informed by results of a standardized linguistically-based test. Therefore, this research asks the question whether the Reading Meaningful Words (RMW) subtest of the EGRA is sufficient to evaluate children’s decoding skills. The current investigation builds on previous research looking into the effects of orthographic depth, syllabic complexity, word length, and use of sub-lexical clusters in Bahasa Indonesia beginning reading. In the first month of the school year, third grade children’s (n = 15) reading performance is recorded on the TMSM and EGRA. Results show that the RMW subtest (n = 50 words) was read 99% correctly in less than 60 s by the third-grade participants. However, in the same time duration, the children are able to read on average 30 words correctly in the TMSM with some mistakes, namely producing words with at least 50% of the sounds in the target words (visual miscues), and regularizations of diphthongs, digraphs and consonant clusters. If the results of EGRA are used to inform educators and authorities in charge of curriculum development to map the stages of reading in Indonesian and devise methods of intervention for the children lagging behind in reading development, it is suggested that the EGRA is not sufficient. Item analysis shows that 40 of the words in the RMW subtest are disyllabic, 9 are trisyllabic, and only 6 of the words contain digraphs, 1 contain diphthongs, and none contains consonant clusters. Yet, three- or four-syllable words are also common in the children’s reading materials, and diphthongs, digraphs, and consonant clusters are common Grapheme Phoneme Correspondence (GPC) in the Indonesian orthography. The design of this subtest, hence, does not facilitate the children to show what they have and have not mastered. The key finding shows children’s reading milestones are influenced by word length and easiness of mapping between phonemes and graphemes and the EGRA needs to incorporate linguistically-based manipulations.