20 CFR § 416.1131 - The one-third reduction rule.
(a) What the rule is. Instead of determining the actual dollar value of in-kind support and maintenance, we count one-third of the Federal benefit rate as additional income if you (or you and your eligible spouse)—
(b) How we apply the one-third reduction rule. The one-third reduction applies in full or not at all. When you are living in another person's household, and the one-third reduction rule applies, we do not apply any income exclusions to the reduction amount. However, we do apply appropriate exclusions to any other earned or unearned income you receive. If you have an eligible spouse we apply the rules described in § 416.1147.
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