A program modification database and method for identifying a candidate entry within the correction database for a particular executable program are disclosed. The program modification database provides a general depository of program changes, referred to herein as substitute program segments, and a set of executable program entries containing program matching criteria and corresponding program changes. The program modification database includes an index. Each entry in the index includes a piece of identifying information for a referenced, corresponding executable program entry. The program modification database architecture is applicable to any type of program segment information for modifying either instruction code or data values within a program. The types of information, within a program matching criteria, taken from an executable program file used to identify a corresponding executable program entry within the program modification database are selectable on an individual basis from an extensible set of executable program information types.