Applicable Large Employers (ALE's) that which to comply with the affordability provision of ACA must use the 9.56% rate for plan years beginning in 2018. The rate for plan years beginning in 2017 is currently 9.69%. A plan year is essentially the start of your contract at renewal. So an employer with a medical plan renewal in April would have a plan year of 4/1/17 to 3/31/18 and the 9.69% rate would apply throughout the plan year. 9.56% would begin on 4/4/18 in this example.
Below is an excerpt out of Rev. Proc. 2017-36 that addresses this (from page 2):
02 Section 36B Required Contribution Percentage for 2018. For plan years beginning in 2018, the required contribution percentage for purposes of § 36B(c)(2)(C)(i)(II) and § 1.36B-2T(c)(3)(v)(C) is 9.56%.
Please reach out to your GPI representative with any questions on this or any other ACA matter.