The place of work PUMA codes are a bit different than the place of current residence PUMA codes. In most cases the two are identical, but in some cases multiple PUMAs combined to form a larger area for the place of work. There are several links at the bottom of the Code Tab for PWPUMA00 that clarify the relationship between PWPUMA00 codes and Census based PUMA codes. Of particular interest may be this excel file with a crosswalk between PWPUMA and 2010 PUMA codes.
Additionally, note that the Census redraws PUMA boundaries every 10 years based on population information gathered from the most recent decennial census. ACS samples incorporate the new PUMAs within a few years of the Decennial Census. In Muli-year ACS files, PUMA boundaires depend on the origional year the respondent was interviewed (via MULTYEAR).
I hope this is helpful. Let us know if you have any additional questions.