For this content analysis study, the author examined and cross-compared the various ways in which eight informal reading inventories (IRIs) published from 2004 to 2008 address key issues relevant to new U.S. federal guidelines and the National Reading Panel's five critical components of reading instruction. Results suggest the IRIs range in technical rigor, with only one providing sufficient reliability data to support use of alternate forms. Measures for comprehension and vocabulary are more common than for fluency, phonemic awareness, and phonics. Some of the IRI authors offer passages in Spanish. All of the IRIs have their strengths and limitations, but each one offers special features that set it apart from the others. Results have implications for literacy-related professionals searching for IRIs well-suited to various educational settings and classroom contexts. (Contains 1 table.)