Vesting BRF, Controlled group

[AATPA]

Controlled group members, one non-profit with a 403B and one for-profit with a 401K:

Same vesting schedule, however the 403(b) excludes service prior to the effective date of the plan, meaning the 401K plan is giving more service credit.

Must I perform BRF testing?  The 401K plan has had no HCEs in prior years but does have one in 2018.  The 403B plan usually has 3 HCE's. 

[justanotheradmin]

how old are the plans? More than 6 years? The older the 403(b) the less of a potential issue. 

Are there any impacted participants? It should be fairly easy to determine. How many 403(b) participants have original dates of hire that pre-date the plan start? How many of those are less than 100% vested? 

Hopefully the answer is zero - and it becomes a moot point. 

[AATPA]

When setting up the K plan, I was told there wouldn't be much employee transfer between the entities, but now, It looks like 1/4 to 1/3 of the 401K participants will have some service at the 403b entity prior to the B effective date and did not have 5 years of service from 11-15.  

B effective date is 2011

K effective date is 2016.

B entity (or some parent version of it) goes back 10+ years earlier than the plan. K entity did not have any payroll until 2016.