D/deaf children of Deaf parents reportedly begin learning finger-spelling as young as thirteen months old, but deaf children born to hearing, nonsigning parents lack natural access to the native (spoken) language of their families, often exhibiting later language development. Forty-four deaf adults participated in a fingerspelling test of decoding-encoding pseudowords. The participants offered self-reported demographic information, including age at initial American Sign Language (ASL) exposure and parent hearing status. Analysis of variance using post hoc grouping of participants revealed significantly higher scores on the fingerspelling test among participants with early ASL exposure (p = 0.000; [eta]p2 = 0.45), and those with two D/deaf parents (p = 0.002; [eta]p2 = 0.23). Development and refinement of a fingerspelling test to be used with both D/deaf and hearing, native, and developing signers should benefit professionals working with D/deaf and hearing children and their D/deaf or hearing parents.