WE have a loan used to purchase a multi-family building where the rents are well below market. The idea is the new owner will take the next 5-7 years to increase the rents to market. They have to go slow because the community has a limit on how much rent can increase each year.

Since the units are below at the time of my loan, and who knows if they will ever actually get to market rate, can I claim this as a CD loan now?

It's all about what the situation is today and fulfilling the "primary purpose". If it qualifies as affordable housing primarily occupied by LMI tenants now then it would qualify as affordable housing. This is all about loans you made in a given year and the impact on the community that year.