The opinion of the court was delivered by: Margaret A. Nagle United States Magistrate Judge
MEMORANDUM OPINION AND ORDER
Plaintiff filed a Complaint on December 24, 2008, seeking review of the denial by the Social Security Commissioner ("Commissioner") of plaintiff's application for supplemental security income ("SSI"). On February 26, 2009, the parties consented to proceed before the undersigned United States Magistrate Judge pursuant to 28 U.S.C. § 636(c). The parties filed a Joint Stipulation on August 10, 2009, in which: plaintiff seeks an order reversing the Commissioner's decision and awarding benefits or, in the alternative, remanding the matter for further administrative proceedings; and defendant seeks an order affirming the Commissioner's decision. The Court has taken the parties' Joint Stipulation under submission without oral argument.
SUMMARY OF ADMINISTRATIVE PROCEEDINGS
On September 4, 2002, filed an application for SSI, in which she alleged to have been disabled since September 1, 1991, due to anxiety, memory loss, partial blindness, and lower back, pelvic, and left shoulder pain.*fn1 (A.R. 66-74.) Plaintiff's past relevant work experience includes the jobs of clothes tagger and prep cook. (A.R. 243, 290, 311-12.)
Plaintiff's application was denied initially and upon reconsideration (A.R. 47-58), and she requested a hearing (A.R. 59). On March 31, 2004, plaintiff, who was represented by counsel, testified at a hearing before Administrative Law Judge F. Keith Varni ("ALJ Varni"). (A.R. 40-46.) On April 30, 2004, ALJ Varni denied plaintiff's application. (A.R. 10-20.) Plaintiff appealed ALJ Varni's decision, and the Appeals Council denied plaintiff's request for review. (A.R. 3-8.) On September 13, 2004, plaintiff sought review in this Court (Case No. EDCV 04-1118-MAN). (A.R. 269.) On March 27, 2006, the Court reversed the decision and remanded the case for further proceedings. (A.R. 268-80.) On April 24, 2006, the Appeals Council vacated ALJ Varni's decision and remanded the case to an Administrative Law Judge. (A.R. 266-67.)
On July 3, 2008, Administrative Law Judge Phillip E. Moulaison ("ALJ") held a hearing, at which plaintiff and others testified. (A.R. 285-318.) On August 22, 2007, the ALJ issued a decision that was partially favorable in that the ALJ found plaintiff to be disabled and entitled to receive SSI as of December 27, 2007, but found she was not disabled prior to that date. (A.R. 237-44.)
SUMMARY OF THE COMMISSIONER'S DECISION
The ALJ found that plaintiff has not engaged in substantial gainful activity since September 1, 1991, the alleged onset date. (A.R. 239.) The ALJ determined that plaintiff has a combination of severe impairments consisting of: a history of chronic lower back, right hip, pelvic, and left shoulder pain; diabetes mellitus; peripheral neuropathy; hypertension; history of hepatitis; history of right eye injury; and obesity. (A.R. 239.) Relying on the December 10, 2002 report of Dr. Linda M. Smith, a psychiatrist who performed a consultative psychiatric evaluation of plaintiff, the ALJ concluded that plaintiff's mood disorder is non-severe. (Id.) The ALJ further determined that plaintiff's impairments, singly or in combination, do not meet or equal any of the impairments listed in 20 C.F.R. Part 404, Subpart P, Appendix 1. (A.R. 240.)
The ALJ determined that, as of December 27, 2007,*fn2 plaintiff's residual functional capacity ("RFC") was for unskilled sedentary work as defined in 20 C.F.R. § 416.967(a), because she needed a cane to walk. (A.R. 240.) The ALJ concluded that, as of December 27, 2007, plaintiff was unable to perform her past relevant work as a clothes tagger or a prep cook (A.R. 243), and based on her age, education, work experience, and RFC, there was not a significant number of jobs in the national economy that she could perform (A.R. 244). Accordingly, a finding of "disabled," as of December 27, 2007, was warranted. (Id.)
With respect to the pre-December 27, 2007 time frame, the ALJ concluded that plaintiff had the RFC to perform unskilled light work with certain limitations. (A.R. 242.) Specifically, the ALJ concluded that plaintiff was able to engage in the following activities with the indicated limitations: sit for six hours in an eight-hour workday; stand and/or walk for six hours in an eight-hour workday; lift and/or carry and push and/or pull 10 pounds frequently and 20 pounds occasionally; climb, balance, stoop, kneel, crouch, and crawl occasionally; reach overhead with the left arm occasionally; and engage in unlimited handling, fingering, and feeling. (A.R. 240.) The ALJ found that, although plaintiff's color vision is unlimited, her right eye vision was limited in near acuity, far acuity, depth perception, accommodation, and field of vision. (Id.) He further found that plaintiff had no communicative or environmental limitations. (Id.)
The ALJ found that, prior to December 27, 2007, there was a significant number of jobs in the national economy that plaintiff could have performed.*fn3 (A.R. 243-44.) The ALJ relied on the Medical-Vocational Guidelines, 20 C.F.R. Part 404, Subpart P, Appendix 2 (the "Grids"), as the basis for concluding that, given plaintiff's age, education, work experience, and RFC for light work prior to December 27, 2007, a finding of "not disabled" was warranted for the period prior to December 27, 2007. (A.R. 244.)
Under 42 U.S.C. § 405(g), this Court reviews the Commissioner's decision to determine whether it is free from legal error and supported by substantial evidence in the record as a whole. Orn v. Astrue, 495 F.3d 625, 630 (9th Cir. 2007). Substantial evidence is "'such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.'" Id. (citation omitted). The "evidence must be more than a mere scintilla but not necessarily a preponderance." Connett v. Barnhart, 340 F.3d 871, 873 (9th Cir. 2003). "While inferences from the record can constitute substantial evidence, only those 'reasonably drawn from the record' will suffice." Widmark v. Barnhart, 454 F.3d 1063, 1066 (9th Cir. 2006)(citation omitted).
Although this Court cannot substitute its discretion for that of the Commissioner, the Court nonetheless must review the record as a whole, "weighing both the evidence that supports and the evidence that detracts from the [Commissioner's] conclusion." Desrosiers v. Sec'y of Health and Human Servs., 846 F.2d 573, 576 (9th Cir. 1988); see also Jones v. Heckler, 760 F.2d 993, 995 (9th Cir. 1985). "The ALJ is responsible for determining credibility, resolving conflicts in medical testimony, and for resolving ambiguities." Andrews v. Shalala, 53 F.3d 1035, 1039-40 (9th Cir. 1995). "Where the evidence as a whole can support either a grant or a denial, [a federal court] may not substitute [its] judgment for the ALJ's." Bray v. Comm'r of Soc. Sec. Admin., 554 F.3d 1219, 1222 (9th Cir. 2009)(citation and internal punctuation omitted).
The Court will uphold the Commissioner's decision when the evidence is susceptible to more than one rational interpretation. Tommasetti v. Astrue, 553 F.3d 1035, 1038 (9th Cir. 2008); Burch v. Barnhart, 400 F.3d 676, 679 (9th Cir. 2005); see also Batson v. Comm'r of Soc. Sec. Admin., 359 F.3d 1190, 1193 (9th Cir. 2004)("if evidence exists to support more than one rational interpretation, we must defer to the Commissioner's decision"). However, the Court may review only the reasons stated by the ALJ in his decision "and may not affirm the ALJ on a ground upon which he did not rely." Orn, 495 F.3d at 630; see also Connett, 340 F.3d at 874. The Court will not reverse the Commissioner's decision if it is based on harmless error, which exists only when it is "clear from the record that an ALJ's error was 'inconsequential to the ultimate non-disability determination.'" Robbins v. Soc. Sec. Admin., 466 F.3d 880, 885 (9th Cir. 2006)(quoting Stout v. Comm'r, 454 F.3d 1050, 1055-56 (9th Cir. 2006)); see also Tommasetti, 533 F.3d at 1038; Burch, 400 F.3d at 679.
Plaintiff alleges the following three issues: (1) whether the ALJ properly considered the vocational expert's testimony; (2) whether the ALJ properly analyzed plaintiff's combination of impairments to determine whether her impairments meet or medically equal an impairment set forth in the Listing of Impairments, 20 C.F.R. Pt. 404, Subpt. A, App. 1 (the "Listings"); and (3) whether the ALJ properly considered plaintiff's obesity. (Joint Stipulation ("Joint Stip.") at 2-3.)
I. No Step Three Error Warranting Reversal Has Been Shown
At Step Three of the five-part sequential evaluation for determining whether a claimant is disabled, the Commissioner must determine whether a claimant's impairment or impairments meet or equal one of the specific impairments set forth in the Listings. 20 C.F.R. § 416.920(a)(4)(iii). The physical and mental conditions contained in the Listings are considered so severe that "they are irrebuttably presumed disabling, without any specific finding as to the claimant's ability to perform his past relevant work or any other jobs." Lester v. Chater, 81 F.3d 821, 828 (9th Cir. 1995). The Listings were "designed to operate as a presumption of disability that makes further inquiry unnecessary." Sullivan v. Zebley, 493 U.S. 521, 532, 110 S.Ct. 865, 892 (1990); see also Lewis v. Apfel, 236 F.3d 503, 512 (9th Cir. 2001). If a claimant shows that her impairments meet or equal a Listing, she will be found presumptively disabled. 20 C.F.R. §§ 416.925-416.926.
For an impairment or combination of impairments to meet a Listing, all of the criteria of that Listing must be satisfied for the requisite durational period. Zebley, 493 U.S. at 530, 110 S.Ct. at 891 (the impairment "must meet all of the specified medical criteria" in the Listing)(emphasis in original); see also 20 C.F.R. §§ 416.909 and 416.925(c)(3); Social Security Ruling ("SSR") 83-19 ("[a]n impairment 'meets' a listed condition in the Listing of Impairments only when it manifests the specific findings described in the set of medical criteria for that listed impairment").
For an impairment or combination of impairments to equal a Listing, the claimant "must present medical findings equal in severity to all the criteria for the one most similar listed impairment." Zebley, 493 U.S. at 531. 110 S.Ct. at 891 (emphasis in original); see also 20 C.F.R. § 416.926(a)-(b); SSR 83-19 (an impairment is "equivalent" to a Listing only if a claimant's symptoms, signs, and laboratory findings are "at least equivalent in severity" to the criteria for the listed impairment most like the claimant's impairment). In making an equivalence assessment, the claimant's impairments "'must be considered in combination and must not be fragmentized in evaluating their effects.'" Lester, 81 F.3d at 829 (citation omitted). A determination of medical equivalence must rest on objective medical evidence. See Lewis, 236 F.3d at 614 ("[a] finding of equivalence must be based on medical evidence only"); Tackett v. Apfel, 180 F.3d 1094, 1100 (9th Cir. 1999) ("[a] generalized assertion of functional problems is not enough to establish disability at step three," because "'[m]edical equivalence must be based on medical findings'"; citation omitted); 20 C.F.R. § 416.929(d)(3) ("In considering whether your symptoms, signs, and laboratory findings are medically equal to the symptoms, signs, and laboratory findings of a listed ...