When the Fair Housing Act was amended in 1989 to include familial status and disability as protected classes, the Act carved out a specific exemption for housing for older persons. The Act established that in order to qualify as senior housing, there must be at least one person who is 55 years of age or older living in at least 80 percent of its occupied units. In other words, a senior housing facility can maintain its status even if there are families with children living there, so long as the 80% threshold is met.
In 1995, this portion of the Act was amended when President Clinton signed into law the "Housing for Older Persons Act (HOPA) of 1995." This Act requires senior housing facilities or communities to establish specific age verification procedures.

Question and Answers Concerning HOPA (1995) - HUD
However, since this amendment, many questions have arisen regarding whether existing communities and facilities can become senior housing after May 3, 2000, which is the expiration date of the transition period as defined by HOPA regulations. The issue of how to address communities who wish to transition into housing for older persons is addressed in the HUD Memo "Conversion to Housing for Older Persons Under the Fair Housing Act and the Housing for Older Persons Act of 1995 (HOPA)"

