Is ftotval a yearly level household income variable?
Is there monthly level household income variable?
First, FTOTVAL represents annual *family* income. See my previous answer for the subtle yet important distinction between household and family.
Second, most of the income variables come from the ASEC (Annual Social and Economic) supplement of the CPS. Therefore, these variables represent annual income figures. You can estimate a monthly figure by dividing annual figures by 12. Other income variables are availabe in the basic monthly samples via the outgoing rotation group (“earner study”) questions. The “earner study” questions concern the respondent’s periodicity of pay, hourly wage, usual weeks worked per year at that rate, usual hours worked a week, and overtime pay. For more details on the “earner study” questions see the notes page here.