There is (what appears to be) a significant unannounced change to table B27011 in the 2013-2017 ACS data (HEALTH INSURANCE COVERAGE STATUS AND TYPE BY EMPLOYMENT STATUS BY AGE). Previously, this table had breakdowns by age, with groups divided into age buckets of 18-64 and 65 or over. Now, there are not age breakdowns. So almost all of the field names have changed.