Why does the CPS December 2015 Food Supplement Survey not merge with the March 2016 ASEC?

I can merge the 2010 CPS December food supp with 2011 ASEC using CPSIDP; And the merge works similarly for subsequent years up to 2015/2016. But I get no merge between the december 2015 food supplement and the 2016 ASEC. Any idea what’s the problem?

This is likely because the variables CPSID and CPSIDP are currently unavailable for the 2016 ASEC sample. The IPUMS CPS team hopes to release these variables before the end of the year. Sorry for any inconvenience this causes.