Previous research has documented conflicting findings regarding the effect of word frequency on spelling in older adults. The current study examines spelling in Hebrew, in which it is easier to define the type of likely misspellings in each word. Younger and older Hebrew speakers spelled 120 single words that differed in word and letter frequency. Results show that all participants made more phonological substitutions of target letters on low-frequency words and on words with low-frequency letters. Yet, younger adults had a lower percentage of correct responses than did older adults, especially on low-frequency words. Vocabulary knowledge eliminated this age effect. We suggest that aging leads to greater reliance on full lexical retrieval of spelling instead of on sublexical phoneme-to-grapheme processing, due to years of exposure to written language, increase in vocabulary, and consolidation of orthographic representations.