FTM has a menu item allowing another FTM tree to be merged into the existing tree. The primary functions of this option are to enable you to select the portion of the "to be merged" tree you want and to enable you to select which persons to merge with which persons in your main database. Compared to many other merger programs, the FTM merge is superior because it is more thorough in searching. FTM picks up many merge candidates the GenMerge (which is specifically designed for mergers) misses. Unfortunately, a few aspects of the search and match process leave the hard work to the user. FTM apparently does not search alternate names, for example. So, if a person has two names, and those names are marked differently as "preferred" in each file, then FTM may not identify them as a potential match. What is worse is that there are insufficient options within the merge dialog box to adequately search the data file for the correct match unless you have written down the full name and understand how it is indexed. The only effective solution I have found is to make a copy of both files to be merged so you can browse both copies while specifying the exact merge you desire. That is highly cumbersome and redundant. The paucity of options extends to the facts to be merged. While in the merge dialog box, it is not possible to view the sources to be merged. So, slight differences in the citations produce duplicate sources that must be edited one at a time. Additionally, there is no control over the specification of the "preferred" spouse or parent. As a result, the default choice of the program silently applies often leaving parent, spouses, and children incorrect identified in the preference priority.