I use data from 1980 to 2017 for the month of March, for variables incomewage, education, occupation2010, union and states.
when trying to declare the IPUMS data as panel on stata there are repeated time values with id as serial no.
It sounds like you are trying to create a panel data set using SERIAL as your linking variable. As noted here, SERIAL is unique only to each household in a given survey month and year. Therefore, it sounds like you just need to identify the correct linking variable(s) for your analysis. Below is some information about linking household with IPUMS CPS data.
CPSID is an IPUMS-CPS defined variable that uniquely identifies households across CPS samples.
If you wish to link the March Basic samples to the March ASEC samples, you can use MARBASECIDP.
I hope this helps.