Short Plan Year BIS

I have an plan that switch from a 9/30 PYE in 2016 to a 12/31 PYE.   This created a short plan year of 10/1/2016 to 12/31/2016.  

My system is counting Breaks In Service (BIS) wrong in my opinion.   It is counting the short plan year as one year.   So I have people who worked <500 in the 4th quarter who terminated in 2017 as showing as having 5 BIS.   It is counting the short plan year as 1 than 2017, 2018, 2019 and 2020 as the next 4.  I think the 2017 terms are forfeiting a year early.  

I am pretty sure that is wrong.

What I don't know is what is the right answer.   Do I have to figure out if the person worked 500 hours in the calendar year?   Do I ignore the short year?   

Any help or guidance is appreciated.

Thanks

My memory is that you would have overlapping periods. So period 1 would be 10/1/16 to 9/30/17, and period 2 would be 1/1/2017 to 12/31/2017. I don't have a citation handy - just my memory. Then 2018. 2019, 2020. Depending upon the hours worked, sounds like your system may be right? 

8 minutes ago, Belgarath said:

My memory is that you would have overlapping periods. So period 1 would be 10/1/16 to 9/30/17, and period 2 would be 1/1/2017 to 12/31/2017. I don't have a citation handy - just my memory. Then 2018. 2019, 2020. Depending upon the hours worked, sounds like your system may be right? 

That is where my research is leading me.    I think the system is wrong in that in no place did I load the 10/1/2016 to 9/30/2017.   This is an annual ESOP so I need to factor that data into it.   If you got regular payrolls for a 4k plan my guess a system could be programmed to do it right.   In this case the 10/1/2016 to 12/31/2016 census fields only have that quarter's hours.   The 1/1/2017 to 13/31/2017 census field only has those hours.   We computed the vesting right back then so I have the 10/1/2016 to 9/30/2017 so I have the data.    The same overlap happens with vesting and break in service calculations as far as I can tell.  

Thanks