We’ll be updating the entire codebook shortly and it will be updated with the next release of data (which is sooner rather than later).
33013 refers to New Hampshire - Merrimack County.
In case we take longer than you need, the first two digits are the State FIPS code (https://cps.ipums.org/cps-action/vari…) and the last three digits are the county which you can find in the codebook.