OPINION OF THE COURT
In this case plaintiff appeals from a district court order reviewing a decision of the Secretary of Health and Human Services (Secretary) denying plaintiff disability benefits after October 16, 1980. The principal issue to be decided by this Court is whether substantial evidence supports the Secretary’s decision. We believe that the Secretary’s decision denying benefits after October 16, 1980 was supported by substantial evidence, and therefore will affirm the judgment of the district court.
I. Statement of Case
Plaintiff filed an application for a period of disability insurance benefits with the Social Security Administration on April 14, 1980. Plaintiff claimed that a back injury prevented him from working after September 19, 1979. The Social Security Administration denied the application initially and again on rehearing. Pursuant to plaintiff’s request, an Administrative Law Judge (“ALJ”) conducted a de novo hearing at which plaintiff appeared with counsel. On February 19, 1981 the ALJ granted plaintiff’s application for disability benefits but for the period September 19, 1979 through October 16, 1980. The ALJ concluded that plaintiff “[was] able to perform sedentary work activity” as of October 16, 1980. (Tr. 22). Therefore, the ALJ found plaintiff not disabled beyond that period. Id.
*752Plaintiff then sought review of the ALJ’s decision in the United States District Court for the Eastern District of Pennsylvania. The parties filed cross-motions for summary judgment. After evaluating the record and findings of the ALJ, the magistrate recommended that the ALJ’s decision be affirmed. The magistrate stated:
The claimant apparently does not argue that the ALJ’s findings and evaluation of his residual functional capacity for sedentary work were fundamentally wrong, but that they were incomplete because the ALJ did not give due consideration to his mental retardation as an impairment which, added to this physical impairments, effectively precluded him from engaging in the “full range” of sedentary work.
(Appendix “App.” B-13).
The magistrate further stated:
The findings of Dr. Spergel indicate that the limitations imposed by the claimant’s mental retardation were not sufficiently restrictive to prevent him from engaging in several forms of sedentary work. (Tr. 189). Moreover, it appears that the ALJ gave due consideration to Dr. Spergel’s report, in particular noting that Dr. Spergel did not believe that the claimant’s limited mental ability would prevent him from engaging in a number of sedentary jobs. (Tr. 21-22).
(App. B-15).
The district court granted defendant’s Motion for Summary Judgment and adopted the Magistrate’s Report. (App. El-1).
II. The Facts
At the time of the administrative hearing plaintiff was 84, had completed a sixth grade education, and was considered illiterate. His employment history included limited work as a trash collector, mover, dishwasher, janitor and grounds keeper. (Tr. 87). He worked as a grounds keeper at St. Agnes Hospital in Philadelphia until his accident, which occurred during the course of his employment. Plaintiff was injured, when he slipped and fell down a number of wet steps on September 19, 1979. (Tr. 48).
Plaintiff underwent substantial medical evaluations and treatment. (Tr. 7-10, 105-207). He was eventually admitted to Riddle Memorial Hospital on February 18,1980 for the surgical removal of an injured disc. He was readmitted on March 3, 1980 for phlebitis which was successfully treated. (Tr. 117-32).
The record contains a number of medical reports summarizing evaluations conducted by various physicians regarding plaintiff’s medical condition. Dr. Erwin R. Schmidt, Jr., an orthopaedic specialist, concluded that plaintiff was disabled from performing his past maintenance work (Tr. 183), but found plaintiff capable of performing sedentary work. (Tr. 204). Similarly, Dr. Robert J. Doman concluded that plaintiff retained the functional capacity for sedentary work. (Tr. 192-95).
Dr. Philip Spergel, a psychologist and vocational expert, also interviewed the claimant. Dr. Spergel found that the claimant was not only illiterate, but that he possessed a “borderline range of intelligence.” (Tr. 188). Dr. Spergel nevertheless found plaintiff capable of performing “all activities of daily living (dressing, bathing, etc.).” (Id. at 187). He also concluded that plaintiff had a good range of motion in his hands, and that plaintiff could sit comfortably for several hours so long as he shifts positions. (Id.). Finally, Dr. Spergel reported that plaintiff admitted that he could lift up to ten pounds. (Id.).
After evaluating plaintiff’s mental and physical limitations, Dr. Spergel concluded that plaintiff was capable of work and identified specific sedentary jobs existing in the national economy within plaintiff’s residual functional capacity. Dr. Spergel stated:
Despite Mr. Olson’s physical limitations resulting from his lumbosacral discomfort and his educational deficits, he still retains transferable skills. His upper extremity psychomotor functions are intact and his gross manipulative skills, aren’t impaired. In addition, his visual organization is acceptable. He stated that he is *753able to sit and stand for reasonable periods of time.
(Id. at 190).
III. Discussion
The issue in this case is whether substantial evidence supports the Secretary’s decision finding plaintiff not disabled after October 16, 1980. 42 U.S.C. § 405(g) promulgates that “[t]he findings of the Secretary as to any fact, if supported by substantial evidence, shall be conclusive.” Courts have defined “substantial evidence” as “ ‘such relevant evidence as a reasonable mind might accept as adequate to support a conclusion,’ ” Richardson v. Perales, 402 U.S. 389, 401, 91 S.Ct. 1420, 1427, 28 L.Ed.2d 842 (1971); see also, Cotter v. Harris, 642 F.2d 700, 704 (3d Cir.1981), pet. for reh. den., 650 F.2d 481 (3d Cir.1981); Lewis v. Califano, 616 F.2d 73, 76 (3d Cir.1980); Smith v. Califano, 637 F.2d 968, 970 (3d Cir.1981). Substantial evidence has also been defined as “enough [evidence] to justify, if the trial were to a jury, a refusal to direct a verdict when the conclusion sought to be drawn from it is one of fact for the jury,” NLRB v. Columbian Enameling & Stamping Co., 306 U.S. 292, 300, 59 S.Ct. 501, 505, 83 L.Ed. 660 (1939).
The process employed to determine whether plaintiff is entitled to benefits involves shifting burdens of proof. As this Court explained in Rossi v. Califano, 602 F.2d 55 (3d Cir.1979):
There is a two-pronged test for social security act disability: (1) determination of the extent of disability; and (2) determination whether that impairment results in inability to engage in substantial gainful activity. A claimant satisfies [his] initial burden of proof by showing that [he] is unable to return to [his] customary occupation. E.g., Stark v. Weinberger, 497 F.2d 1092 (7th Cir.1974); Baker v. Gardner, 362 F.2d 864 (3d Cir.1966). Once [he] has made such a demonstration, the burden of proof shifts to the Secretary to show that the claimant given [his] age, education and work experience, has the capacity to perform specific jobs that exist in the national economy. E.g., Lewis v. Weinberger, 541 F.2d 417 (4th Cir. 1976); Hernandez v. Weinberger, 493 F.2d 1120 (1st Cir.1976).
Id. at 57.
In the instant case it is undisputed that plaintiff satisfied his burden of establishing disability from September 19, 1979 to October 16,1980 as defined by the Social Security Act, 42 U.S.C. § 423(d)(5). In short, it is agreed that, at the very least, the plaintiff is a “younger (age 18^4),” illiterate and unskilled individual who is unable to return to his past work.
Once plaintiff met the above threshold requirement, the burden fell upon the Secretary to show claimant, considering age, education, mental and physical limitations and work experience “has the capacity to perform specific jobs that exist in the national economy.” Rossi v. Califano, 602 F.2d at 57.
In determining whether plaintiff possesses the residual functional capacity to engage in substantial gainful activity, the Secretary may be guided by the regulations at 20 C.F.R. § 404.1501, et seq. The Social Security Administration adopted these guidelines to ensure consistency in the Secretary’s resolution of disability claims. These regulations provide for a five-step sequential evaluation giving consideration to (1) whether the claimant is currently working; (2) the severity of his impairment; (3) the nature of his impairment; (4) his ability to do relevant past work; and (5) his ability to do any work. Additionally, these regulations provide medical-vocational guidelines and tables in 20 C.F.R. Sub-part P, Appendix 2, to be applied once the Secretary has established whether the claimant’s maximum sustained work capability is limited to sedentary, light, medium or heavy work.
Appellant makes two arguments. First, he argues that in completing the fifth step of the evaluation process the AU applied an incorrect legal standard. Second, he insists that the ALJ’s finding of no disability beyond October 16, 1980 was not supported by substantial evidence.
*754Appellant points specifically to Finding # 11 of the ALJ as evidence of the ALJ’s alleged error. Finding # 11 states:
... 20 C.F.R. Section 404.1569 and Rule 201.23 Table No. 1 of Appendix 2, Sub-part P, Regulations No. 4, direct that, as of October 16, 1980, the claimant, considering his maximum sustained work capability, age, education, and work experience, be found “not disabled” from that date ... (emphasis added).
(Tr. 23). Appellant suggests that the ALJ failed to make any finding with regard to plaintiff’s non-exertional impairment1 which would have precluded the use of grids found in Section 404.1569 and Rule 201.23, Table No. 1 of Appendix 2, Subpart P, Regulation No. 4.2 The existence of plaintiff’s non-exertional impairment, appellant suggests, would operate to place plaintiff in between the various grids, and therefore the ALJ’s use of the word “directed” with regard to the effect of the regulations evidences a clear error.
We disagree with appellant’s contention. The ALJ in the instant case considered “all of the testimony given at the hearing and the documents contained in the exhibit file” (Tr. 20) and made a decision supported by substantial evidence as required by law. (Tr. 20). Based upon a detailed and express evaluation of that evidence, the ALJ made twelve specific findings:
FINDINGS
1. That the claimant met the specific earnings requirements for disability insured status under the Act on September 19, 1979;
2. That the medical evidence of record establishes that the claimant has been treated for orthopedic impairment of the low back with surgery on February 18, 1979, and a later bout of thrombophlebitis of the right leg;
3. That, based on credibility and evidence of record, I do not find that the claimant’s subjective symptoms, including those of pain, would have prevented him from engaging in substantial gainful work activity from October 16, 1980;
4. That the claimant’s impairments prevented him from engaging in substantial gainful work activity, however, commencing on September 19, 1979, and continued for a period of at least 12 months, until October 16, 1980, but not thereafter;
5. That the greater weight of the medical evidence establishes that these significant impairments lasted for a period of 12 months at a level of severity so as to cause the inability of the claimant to engage in substantial gainful activity;
6. That the claimant is unable to perform his past relevant jobs;
7. That, as of October 16, 1980, the claimant had the maximum sustained work capability for sedentary work, as defined in section 404.1567 of Subpart P, Regulations No. 4;
8. That the claimant was bom on December 16, 1945, and is a younger individual;
*7559. That the claimant completed the sixth grade in school, but is illiterate;
10. That the claimant’s past work activities did not impart skills that are transferable to work other than that previously performed;
11. That section 404.1569 and Rule 201.-23, Table No. 1 of Appendix 2, Sub-part P, Regulations No. 4, direct that, as of October 16, 1980, the claimant, considering his maximum sustained work capability, age, education, and work experience, be found “not disabled” from that date, and through the date of this decision;
12. That the claimant was not under a “disability” as defined in the Social Security Act, as amended, after October 16, 1980, and through the date of this decision.
(Tr. 22-23).
These findings indicate that the ALJ considered competing medical evidence, (see Finding # 5) as well as other evidence and resolved any conflict in evidence in favor of finding a 12-month closed period of disability instead of a period in excess of 12 months. Moreover, the ALJ’s Report indicates that several doctors found plaintiff capable of performing sedentary work, one of whom, Dr. Spergel, identified specific sedentary jobs, existing in the national economy, for which plaintiff retained the residual functional capacity to perform. (Tr. 190). In short, these Findings and other evidence in the record constitute substantial evidence.
As in many other social security cases which come before us, the instant claimant made a compelling argument about his disability; it could have persuaded some fact finders to rule in his favor. Where the record establishes beyond dispute that the claimant had a serious injury, has a “borderline range of intelligence” and is illiterate, and where an orthopedic specialist testified that claimant was incapable of performing his past maintenance work, certainly there is sufficient evidence to justify an award in his favor. But in view of the ALJ’s specific findings and his detailed consideration of all of the evidence, including the combined effect of several impairments, we cannot say that as a matter of law the ALJ erred in resolving every major conflict in evidence against the claimant. Such is the nature of administrative adjudications and the constraints on our appellate review process. Thus, we will affirm the district court in upholding the ALJ’s decision as supported by substantial evidence.