Opinion of the Court
Congress added a clarifying provision: "Nothing in [the FHA] prohibits a person engaged in the business of furnishing appraisals of real property to take into consideration factors other than race, color, religion, national origin, sex, handicap, or familial status." 42 U. S. C. §3605(c). Second, Congress provided: "Nothing in [the FHA] prohibits conduct against a person because such person has been convicted by any court of competent jurisdiction of the illegal manufacture or distribution of a controlled substance.” §3607(b)(4). And finally, Congress specified: "Nothing in [the FHA] limits the applicability of any reasonable . . . restrictions regarding the maximum number of occupants permitted to occupy a dwelling." §3607(b)(1).
The exemptions embodied in these amendments would be superfluous if Congress had assumed that disparate-impact liability did not exist under the FHA. See Gustafson v. Alloyd Co., 513 U. S. 561, 574 (1995) ("[T]he Court will avoid a reading which renders some words altogether redundant"). Indeed, none of these amendments would make sense if the FHA encompassed only disparate-treatment claims. If that were the sole ground for liability, the amendments merely restate black-letter law. If an actor makes a decision based on reasons other than a protected category, there is no disparate-treatment liability. See, e.g., Texas Dept. of Community Affairs v. Burdine, 450 U. S. 248, 254 (1981). But the amendments do constrain disparate-impact liability. For instance, certain criminal convictions are correlated with sex and race. See, e.g., Kimbrough v. United States, 552 U. S. 85, 98 (2007) (discussing the racial disparity in convictions for crack cocaine offenses). By adding an exemption from liability for exclusionary practices aimed at individuals with drug convictions, Congress ensured disparate-impact liability would not lie if a landlord excluded tenants with such convictions. The same is true of the provision allowing for reasonable restrictions on occupancy. And the