United States Court of Appeals For the Seventh Circuit ____________________ No. 20-2598 RANDALL RUENGER, Plaintiff-Appellant, v. KILOLO KIJAKAZI, Acting Commissioner of Social Security, Defendant-Appellee. ____________________

Appeal from the United States District Court for the Eastern District of Wisconsin. No. 19-CV-1160 — Nancy Joseph, Magistrate Judge. ____________________

ARGUED NOVEMBER 16, 2021 — DECIDED JANUARY 14, 2022 ____________________

Before BRENNAN, SCUDDER, and JACKSON-AKIWUMI, Circuit Judges. PER CURIAM. When a person applies for disability benefits, the Social Security Administration evaluates whether signifi- cant numbers of jobs exist in the national economy for some- one with that person’s limitations. Administrative law judges often rely on vocational experts to estimate these job numbers. But ALJs cannot afford complete discretion to vocational 2 No. 20-2598 experts. Instead, when a claimant challenges a vocational ex- pert’s job-number estimate, the ALJ must inquire whether the methodology used by the expert is reliable. In this case, the vocational expert enlisted by the agency to estimate the num- ber of jobs suitable for Randall Ruenger omitted crucial de- tails about her methodology, such as the source of her job numbers and the reason she used the equal distribution method. But the ALJ nevertheless relied on the expert’s testi- mony. Because substantial evidence does not support the ALJ’s decision, we vacate and remand for further proceed- ings. I Randall Ruenger applied for benefits in 2015, alleging that he had limited use of his left arm and mental impairments in- cluding anxiety and depression. He eventually received a hearing before an ALJ in 2018. Applying the five-step inquiry found in 20 C.F.R. § 416.920, the ALJ determined that Ruenger had not worked within the claim period (step one); that his mental and physical impairments were severe (step two) but did not presumptively establish a disability (step three); and that he had the capacity to perform light work with certain physical and social limitations (step four). At the fifth and fi- nal step of the inquiry, the ALJ determined—based on a voca- tional expert’s testimony—that Ruenger could still perform jobs that exist nationwide in significant numbers. Accord- ingly, the ALJ denied Ruenger’s application. Some context about step five is necessary. At this step, the agency bears the burden of demonstrating that there are sig- nificant numbers of jobs in the national economy for someone with the claimant’s abilities and limitations. See 20 C.F.R. § 416.960(c)(2). Because estimating job numbers No. 20-2598 3 is no easy feat, ALJs commonly rely on the testimony of voca- tional experts—professionals with experience in job place- ment and knowledge of working conditions. See Biestek v. Ber- ryhill, 139 S. Ct. 1148, 1152 (2019); 20 C.F.R. § 416.966(e). To provide tailored job-number estimates, vocational ex- perts use various sources, and the expert here consulted three. The first is the Dictionary of Occupational Titles (DOT), a publi- cation produced by the Department of Labor that lists job ti- tles and their requirements. The DOT was last revised thirty years ago, leaving many of its job descriptions outdated. See Browning v. Colvin, 766 F.3d 702, 709 (7th Cir. 2014) (“No doubt many of the jobs [in the DOT] have changed and some have disappeared.”). Since 2008, the Social Security Admin- istration has been working on a project to replace the DOT with an updated publication—a development this court con- tinues to invite.