The opinion of the court was delivered by: Padova, J.
Plaintiff Lisa Parks brought this action on behalf of her minor child, K.D., pursuant to 42 U.S.C. § 1383(c)(3), seeking judicial review of the decision of the Commissioner of the Social Security Administration, Michael Astrue ("Commissioner"), denying her claim for Supplemental Security Income ("SSI") benefits under Title XVI of the Social Security Act. After Plaintiff filed a Request for Review of the decision denying her claim for SSI benefits, we referred the matter to Magistrate Judge Lynne A. Sitarski, who issued a Report and Recommendation ("R & R") that Plaintiff's Request be denied and that judgment be entered in favor of the Commissioner. Plaintiff filed timely objections to the R & R. For the reasons that follow, we overrule Plaintiff's objections and approve and adopt Magistrate Judge Sitarski's R & R.
This proceeding arises from the denial of Plaintiff's April 10, 2003 application for SSI benefits on behalf of K.D., who was then approximately seven years old, based upon a disability dating from August 1, 2001.*fn1 (R. at 124-30.) Plaintiff alleged in the application that K.D. was disabled as a result of asthma, behavior problems, and attention deficit hyperactivity disorder ("ADHD"). (Id. at 77.) This application was denied by the Social Security Administration on July 28, 2003 because the medical evidence showed that K.D. had been treated for his conditions, did not require frequent hospitalization for his asthma, was in a regular classroom with extra assistance, and was able to do age-appropriate activities. (Id.) Plaintiff appealed and an Administrative Law Judge ("ALJ") held a hearing on May 12, 2004. (Id. at 43-56.) The ALJ denied Plaintiff's application on June 14, 2004. (Id. at 62-72.) Plaintiff requested review by the Appeals Council, which remanded the application to the ALJ on March 7, 2006. (Id. at 100, 110-12.) The ALJ held a second hearing on April 26, 2006. (Id. at 29-42.) The ALJ denied Plaintiff's application for a second time on July 27, 2006. (Id. at 12-27.)
The ALJ made the following findings on July 27, 2006*fn2: (1) K.D. was a school-age child when the application was filed and at the time of the decision; (2) K.D. was 10 years old and had not engaged in substantial gainful activity at any relevant time; (3) K.D. had the severe impairments of asthma and ADHD; and (4) K.D. did not "have an impairment or combination of impairments that functionally equals the listings...." (Id. at 17.) The ALJ reviewed K.D.'s functional limitations in each of the six functional domains and found that he had (1) a moderate, but less than marked, limitation in acquiring and using information, with the expectation that he would improve in this area with the provision of additional learning services (id. at 23); (2) a less than marked limitation in attending and completing tasks (id. at 24); (3) marked limitations in interacting with and relating to others (id. at 25); (4) no limitation in moving about and manipulating objects (id. at 26); (5) no limitation in caring for himself (id.); and (6) no limitation in health and physical well-being, as his asthma was under good control (id. at 27.).
Plaintiff sought review of the ALJ's July 27, 2006 decision. (Id. at 11.) The Appeals Council denied review on July 28, 2008. (Id. at 6-8.) Plaintiff filed the instant action on September 24, 2008, and maintains that the ALJ erred by failing to find that K.D. had a marked limitation in his ability to acquire and use information or, in the alternative, by failing to find that K.D. had an extreme limitation in his ability to interact with and relate to others. (Pl.'s Br. at 4.) In support of her arguments, Plaintiff placed significant emphasis on behavioral assessments, psychological evaluations, and other tests of K.D. that were performed after the ALJ issued his decision (the "new evidence"). (Id. at 9-12.)
The Magistrate Judge declined to review the new evidence and recommended that the new evidence did not warrant a remand to the Commissioner pursuant to sentence six of 42 U.S.C. § 405(g)*fn3 (a "sentence six remand"). After reviewing evidence which had been of record before the ALJ in detail, the Magistrate Judge recommended that the ALJ properly found that K.D. had only a marked limitation in interacting and relating with others and had a less than marked limitation in acquiring and using information, and consequently recommended that we deny Plaintiff's request for review. Plaintiff objects only to the Magistrate Judge's failure to consider the new evidence and recommendation that the new evidence does not warrant a sentence six remand to the Commissioner.*fn4
Judicial review of the Commissioner's final decision is limited, and the ALJ's findings of fact will not be disturbed if they are supported by substantial evidence. Rutherford v. Barnhart, 399 F.3d 546, 552 (3d Cir. 2005) (citing 42 U.S.C. § 405(g) and Plummer v. Apfel, 186 F.3d 422, 427 (3d Cir. 1999)). Substantial evidence is defined as "'such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.'" Id. at 552 (quoting Reefer v. Barnhart, 326 F.3d 376, 379 (3d Cir. 2003)). "It is 'more than a mere scintilla [of evidence] but may be less than a preponderance.'" Id. (quoting Ginsburg v. Richardson, 436 F.2d 1146, 1148 (3d Cir. 1971)). The ALJ's legal conclusions are subject to plenary review. Schaudeck v. Comm'r of Soc. Sec. Admin., 181 F.3d 429, 431 (3d Cir. 1999) (citing Krystoforski v. Chater, 55 F.3d 857, 858 (3d Cir. 1995)).
We review de novo those portions of a Magistrate Judge's report and recommendation to which objections are made. 28 U.S.C. § 636(b)(1). We may accept, reject, or modify, in whole or in part, the Magistrate Judge's findings or recommendations. Id.
A. Consideration of the New Evidence
Plaintiff contends that the Magistrate Judge erred in failing to consider the new evidence, which she had submitted to the Appeals Council but had not submitted to the ALJ. With one exception, Plaintiff acquired the new evidence during the period following the ALJ's July 27, 2006 decision denying SSI benefits to K.D., and prior to the Appeals Council's July 28, 2008 decision denying her request for review of the ALJ's decision.*fn5 (See R. at 613-742.) It has long been the rule in this Circuit that "evidence that was not before the ALJ cannot be used to argue that the ALJ's decision was not supported by substantial evidence." Mathews v. Apfel, 239 F.3d 589, 594 (3d.Cir. 2001) (citing Jones v. Sullivan, 954 F.2d 125, 128 (3d Cir. 1991)). We conclude that the Magistrate Judge properly declined to consider ...