|Abstract:||Blocking in inflection occurs when a morphological exponent prevents the application of another exponent expressing the same feature value, thus barring the occurrence of multiple exponents of a single morphosyntactic feature value. In instances of extended exponence, more than one exponent in the same word realizes the same feature value. We provide a unified account of blocking and extended exponence that combines a realizational approach to inflection with Optimality Theory (Realization Optimality Theory), encoding morphological realization rules as ranked violable constraints. The markedness constraint *FEATURE SPLIT bars the realization of any morphosyntactic feature value by more than one exponent. If *FEATURE SPLIT ranks lower than two or more realization constraints expressing the same feature value, then we observe extended exponence. Otherwise, we find blocking of lower-ranked exponents. We show that Realization Optimality Theory is superior to various alternative approaches to blocking and extended morphological exponence.