Why do I get Type 3 Analysis of Effects in linear regression in SAS EM

[StatDave]

I'm not sure about your particular analysis, but depending on how it is done it is possible for the Type 3 test to differ from the individual parameter test for a variable that only has a single parameter (such as if it is continuous). This can be because a different type of test might be used for the two tests. This is the case with analyses done by PROC GENMOD or PROC GEE as described in this note.