Congressional leaders reached agreement today on a fiscal year 2018 omnibus spending bill that includes a 12.5 percent increase in low-income housing tax credit (LIHTC) allocations for four years and a provision from the Affordable Housing Credit Improvement Act of 2017. The 12.5 percent boost applies to the 2018 LIHTC allocations and will be in effect for 2019, 2020 and 2021. Barring an extension, the LIHTC annual allocation would revert to the previous levels (adjusted for inflation) in 2022. Also included in the omnibus bill is a provision to allow income averaging for LIHTC properties on a permanent basis.
The Notes from Novogradac blog has a more in-depth explanation of the affordable housing provisions.