From the Fed RPPR Guidance (version: 01.31.2014), link here. Bolded for faster reading. This is from
major notes: (for personnel effort table only)
-only report PI + those who have 1.0 cal months effort or more.
– For PI only, if their effort is < 0.41 Cal. Month, then round to zero.
Include (1) the PD/PI regardless of effort devoted to the project and (2) each person who has worked at least one person month per year on the project during the reporting period, regardless of the source of compensation.
Round to the nearest whole person month that the individual worked on the project. For example, if the individual worked 2.25 person months, indicate 2 person months. If the individual worked 4.7 person months, indicate 5 person months. If the PD/PI worked 0.5 to 1 person month, round up to 1 person month. If the PD/PI worked 0.1 to 0.4 person month, round down to 0 (zero).
Person months reported on the RPPR are intentionally rounded to the nearest whole number to provide for generalized reporting consistent across federal agencies that support research activities. Although it is possible to report 0 (zero) person month for the PD/PI on the RPPR if the PD/PI worked .1 to .4 person month, a PD/PI must have measurable effort.