Rasheeda Kambra Jones applied for and was denied Supplemental Security Income benefits under Title XVI of the Social Security Act. The denial was based on the ground that her impairments did not meet, equal, or functionally equal the childhood or adult listings for mental retardation. The Administrative Law Judge (ALJ) found that Ms. Jones was not disabled because, although she did suffer from mental retardation, she did not have the kind of additional impairment necessary to qualify her for the listing claimed. The Appeals Council, acting for the Commissioner, agreed. Ms. Jones appeals from a decision of the United States District Court for the Northern District of Iowa, which upheld this decision to deny her benefits. On appeal, she argues that the combination of her mental, learning, and communications limitations satisfies the criteria for a finding of disability. We hold that the Commissioner’s decision was not supported by substantial evidence, reverse the judgment of the District Court, and remand with directions to award benefits.
I.
This Court reviews a decision by an ALJ “to determine whether it is supported by substantial evidence on the record as a whole.” Bailey v. Apfel, 230 F.3d 1063, 1065 (8th Cir.2000); 42 U.S.C. §§ 405(g), 1383(c)(3) (1998). Substantial evidence is defined as evidence that a reasonable person would find adequate to support the conclusion. Bailey, at 1065.
Ms. Jones’s application for SSI benefits was filed a little more than one month before her 18th birthday, and so was evaluated under the standards for both childhood disability (for the brief period before she reached her majority) and adult disability. The standards for evaluation of childhood and adult disability are similar but not identical. In order to determine whether a child is eligible for SSI benefits on the basis of disability, an ALJ must first determine whether the child is engaged in substantial gainful activity. 20 C.F.R. § 416.924(b) (2000). If the child is not engaged in such activity, the ALJ must determine whether the child’s impairment or combination of impairments is severe. 20 C.F.R. § 416.924(c) (2000). If the impairment is severe, the ALJ must then determine whether a child’s impairments meet, medically equal, or functionally equal, a listed impairment set out in Ap*699pendix 1 of 20 C.F.R. Part 404, Subpart P. 20 C.F.R. § 416.924(d) (2000). In the event a child’s impairments do not meet or medically equal a listed impairment, the ALJ must assess all functional limitations to decide whether they functionally amount to a listed impairment. 20 C.F.R. § 416.926(a) (2000). If the impairments do not meet, medically equal, or functionally equal a listed impairment, a child will not be found disabled. 20 C.F.R. § 416.926(d) (2000).
To find an adult disabled, an ALJ normally engages in a five-step analysis. 20 C.F.R. § 404.1520(a)-(f) (2002); Bowen v. Yuckert, 482 U.S. 137, 140, 107 S.Ct. 2287, 96 L.Ed.2d 119 (1987). The first three steps of this analysis replicate the analysis for disability in a child described above. If a listed impairment is not met or equaled, the fourth step is reached, at which the ALJ determines whether the claimant is prevented from performing the work she has performed in the past. If she is able to perform this work, she is not considered disabled. If she is not able to perform work she has done before, the ALJ must determine whether she is capable of performing other work in the national economy given her age, education, and work experience. Trenary v. Bowen, 898 F.2d 1361, 1363 n. 3 (8th Cir.1990) (citing Bowen v. Yuckert, 482 U.S. at 140-142, 107 S.Ct. 2287); 20 C.F.R. § 404.1520(a)-(f) (2002).
The present case is unusual, in that the fourth and fifth steps of the sequential are irrelevant and need not be reached. If the claimant wins at the third step (a listed impairment), she must be held disabled, and the case is over. E.g., Sird v. Chater, 105 F.3d 401, 402, 403 n. 6 (8th Cir.1997). In this particular case, the claimant concedes that she must win, if at all, at the third step. If she does not meet the criteria for a listed impairment, she gives up, so to speak, and does not ask that the analysis proceed to the fourth and fifth steps. We therefore need not be concerned with, and do not discuss, any of the evidence or findings that relate to these last two steps.
II.
Section 12.05(C) provides that mental retardation is sufficiently severe to constitute a listed disability for an adult when the claimant has: (1) “[a] valid verbal, performance, or full scale IQ of 60 through 70,” and (2) “a physical or other mental impairment imposing additional and significant work-related limitation of function.” 20 C.F.R. Pt. 404, Subpt. P, App. 1, § 12.05(C) (2002).2 A physical or other mental impairment is sufficient to satisfy the second part of this test when such impairment “has a ‘more than slight or minimal’ effect on [the claimant’s] ability to perform work.” Buckner v. Apfel, 213 F.3d 1006, 1011 (8th Cir.2000), quoting Cook v. Bowen, 797 F.2d 687, 690 (8th Cir.1986). It is undisputed that Ms. Jones’s IQ score meets the criteria of Listing 12.05(C) (adult) and 112.05(D) (child). However, the ALJ found that she lacked the necessary “additional and significant” limitation required under these sections for a finding that her impairment meets or equals a listed impairment. On appeal, Ms. Jones claims, among other things, that her limitations in speech amount to the required “additional and significant” limitation which, coupled with her low intelligence, should entitle her to SSI benefits. Notably, the Commissioner did not discuss Ms. Jones’s claimed speech and communications impairment as distinct from her *700low I.Q., and made no determination that it had no more than a “slight or minimal” effect on her ability to work.
In considering whether substantial evidence exists to uphold the Commissioner’s finding, we must first address whether this claimant’s speech impairment is more than “slight or minimal.” In our view, the record before us not only permits, but requires, an affirmative answer to that question. The ALJ found that Ms. Jones was incapable of performing work that required public speaking or reading aloud. According to the trier of fact, Ms. Jones is unsuited to work “in any job where she would be forced to speak in public to groups of people.” Joint Appendix 16. Ms. Jones responded to her attorney’s questions about her anxiety in public situations by stating that she gets nervous “[w]hen I have to be in front of people or have to say a speech or something.” Admin. R. at 62. Our dissenting colleague points out that there was no specific reference to a speech defect as such in the record before the ALJ. The ALJ’s opinion, however, id. at 18, does refer to a 1998 diagnosis by a state agency clinical psychologist, Janet McDonough, Ph.D., that “the claimant had marked limitation in the area of cognitive/communication function ....” In addition, she had received speech therapy from the first through the fourth grades.
If this were the only evidence in the' record, we might well agree that the claimant’s speech impairment has not been shown to be something separate from her low I.Q. Evidence developed only four days before the filing of the ALJ’s opinion, but too late to be discussed in the opinion, however, casts this record in a significantly different light. Our dissenting colleague, post p. 702, minimizes this evidence on the ground that it comes only from one expert evaluator, referring to “a one-time evaluator’s recommendation, submitted after the ALJ’s decision, that Ms. Jones continue with speech therapy.” With respect, we read the record somewhat differently. The full report from the University of Iowa Hospitals and Climes, Exhibit AC-1 before the Appeals Council, is instructive. The attending physician, Don C. Van Dyke, M.D., first noted that the claimant had “a long-standing history of educational problems ....” Id. at 244. He then added: “She needed speech therapy in school. She is still involved with speech therapy.” Id. at 245. She has “[a] long history of language problems and school difficulty.” Ibid. She has “[a] long history of speech problems and right now is still continuing to get articulation therapy.” Ibid. Dr. Van Dyke then gave his impression, id. at 246, and he gave it, significantly we think, in two parts:
1. Borderline intellectual abilities
2. Articulation deficits
The indication is that Dr. Van Dyke considered the claimant’s articulation deficits, or speech defect, as an impairment distinct from her borderline intellectual abilities.
Further, Judy Jordan, M.S., also of the University of Iowa, referred to the claimant’s “language-based learning disorder.” Id. at 247. A speech and language evaluation by two other experts added details:
Many errors resulted from the omission of words, substitution of words, and rearranging of the syntactical structure.
Id. at 250.
Her errors largely consisted of word substitutions, (i.e., “foot” for “fort”) and reversals in word order.
Id. at 251.
The report concluded:
In view of today’s findings, it is recommended that Rasheeda receive support services in educational settings. Rash-*701eeda will benefit from clarification of language presented utilizing basic vocabulary terms. In addition, visual cues, such as word webs, graphs, and other pictures and/or illustrations, would be beneficial for Rasheeda to improve her comprehension of language.
Id. The entire report was approved not only by Dr. Van Dyke, an associate professor of pediatrics, but also by Mary Corbin, LISW, Service Facilitator. The Appeals Council considered the additional evidence, id. at 5, but made no specific determination or finding about a speech impairment. Certainly it did not find either that the claimant’s speech impairment was “slight or minimal,” or that her speech impairment was not a condition distinct from her low I.Q.
In these circumstances, and given the appropriateness of additional treatment, we cannot see how the speech impairment can fairly be characterized as “slight or minimal.” Nor can it be viewed as simply a peripheral effect of her low intelligence, since the problem has persisted from an early age, and specific treatment for the condition has been recommended. The problem is not merely one of cognition (I.Q.), but also of expression (for example, an inability to put words in the proper order). Communications difficulty is a real impairment that limits claimant’s employment opportunities to the rare job which requires no regular, responsive communication. To be sure, there is evidence in the record that points the other way, as the dissent properly emphasizes, but the overwhelming weight of the most recent evidence is in favor of the claimant.
The Commissioner argues that Ms. Jones’s speech impairment is not so severe as that of the claimant in Bailey v. Apfel, 230 F.3d 1063 (8th Cir.2000), a similar case cited and distinguished by the District Court. This may well be true. The question before us, however, is not simply whether Ms. Jones’s speech difficulties are as severe as Bailey’s were. The question, instead, is whether substantial evidence on the record as a whole can support a finding that Ms. Jones’s difficulties are “slight or minimal.” We hold that it cannot.
Accordingly, the judgment of the District Court is reversed, and this cause is remanded to that Court with instructions to remand the matter to the Commissioner for the computation and award of benefits.
It is so ordered.
. The phrase “work-related" does not occur in the parallel definition for children, § 112.05(D). Otherwise, the two definitions are not materially different.