The Ninth Circuit affirmed the district court’s order upholding the Commissioner of Social Security’s denial of Daniel B. Boos’s application for disability benefits. The court applied a de novo standard of review, reversing only if the administrative law judge’s (ALJ) decision was based on legal error or not supported by substantial evidence in the record. The court held that substantial evidence supported the ALJ’s findings across all key issues. First, the ALJ correctly determined that Boos’s spine disorder was not a severe impairment, relying on medical records and testimony indicating only mild to moderate limitations; the court noted that where evidence is susceptible to multiple rational interpretations, the ALJ’s decision must be upheld. Second, the ALJ properly assessed Boos’s residual functional capacity by considering his mental impairments, noting that while Boos claimed an unspecified personality disorder and ADHD, he provided no medical documentation for these conditions, and the ALJ still accounted for potential symptoms based on available evidence. Third, the ALJ correctly concluded that Boos did not meet the statutory listing criteria for disability, finding only moderate limitations in mental functioning areas rather than marked ones. Fourth, the ALJ provided clear and convincing reasons to reject Boos’s subjective testimony regarding symptom severity, citing inconsistencies between his reported symptoms and his self-described daily activities, as well as evidence that his impairments responded well to treatment. Finally, the court rejected arguments regarding an incomplete hypothetical posed to a vocational expert and a claim of legal error based on *Loper Bright Enterprises v. Raimondo*, holding that both issues were forfeited because they were not raised before the district court. As a result of this affirmation, the denial of Boos’s disability benefits application remains in effect, and he is not entitled to the requested social security payments.