The Census Bureau release schedule is here: https://www.census.gov/programs-surve…
Is IPUMS-USA updated with 2015 one month after the 1-Year PUMA data are released (November 16), or one month after the 5-Year PUMA data are released (January 17)?
IPUMS will release the 1-year PUMA data and the 5-year PUMA data separately. Typically the IPUMS-USA team requires a month to harmonize the data, so you can expect 2015 ACS 1-year file by the end of November and the 5-year file by the end of January.