In the 2014 SIPP Panel, health insurance was collected in "spells" with distinct beginning and ending months.  Beginning in Wave 2, the survey brought forward coverage data from the prior wave.  Respondents who had ongoing insurance coverage as of Wave 1 were reminded of their previous responses and could indicate whether their previously reported insurance spell was still ongoing.  While this practice was intended to help promote recall, some interviewers did not remind respondents of their previous responses and instead started a new health insurance spell immediately following the spell entered at the prior interview.  For such insurance spells, if plan details matched across Waves 1 and 2, we merged the spell and assumed the interviewer intended to continue the spell previously recorded.  However, if plan details did not match across waves, we left information as reported. As a result, users may notice that more health insurance spells begin and end in the first few months of the reference period when SIPP interviews took place.  These additional spells were more common for private insurance. 

Users should examine the data and decide if such adjacent spells reflect true changes in insurance coverage or reflect the transition between the Wave 1 and 2 reports.