ORDER
EDMUND F. BRENNAN, Magistrate Judge.
Plaintiff seeks judicial review of a final decision of the Commissioner of Social Security ("Commissioner") denying his application for a period of disability and Disability Insurance Benefits ("DIB") under Titles II of the Social Security Act. The parties have filed cross-motions for summary judgment. For the reasons discussed below, plaintiff's motion for summary judgment is granted, the Commissioner's motion is denied, and the matter is remanded for further proceedings.
I. BACKGROUND
Plaintiff filed applications for a period of disability and DIB, alleging that he had been disabled since February 5, 2008. Administrative Record ("AR") 147-148. His application was denied initially and upon reconsideration. Id. at 82-86, 90-94. On July 31, 2013, a hearing was held before administrative law judge ("ALJ") David M. Blume. Id. at 36-64. Plaintiff was represented by counsel at the hearing, at which he testified. Id.
On April 18, 2011, the ALJ issued a decision finding that plaintiff was not disabled under sections 216(i) and 223(d) of the Act.1 Id. at 15-21. The ALJ made the following specific findings:
1. The claimant last met the insured status requirements of the Social Security Act on September 30, 2011.
2. The claimant did not engage in substantial gainful activity during the period from November 17, 2009, through his date last insured of September 30, 2011 (20 CFR 404.1571 et seq.).
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3. Through the date last insured, the claimant had the following severe impairments: carpal tunnel syndrome, degenerative disc disease of the lumbar and cervical spine, status post bilateral shoulders arthroplasty (20 CFR 404.1520(c)).
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4. Through the date last insured, the claimant did not have an impairment or combination of impairments that met or medically equaled the severity of one of the listed impairments in 20 CFR Part 404, Subpart P, Appendix 1 (20 CFR 404.1520(d), 404.1525and 404.1526).
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5. After careful consideration of the entire record, the undersigned finds that, through the date last insured, the claimant has the residual functional capacity to perform light work as defined in 20 CFR 404.1567(b) except the claimant could occasionally climb ramps/stairs, kneel, stoop, crouch, and crawl. He could not climb ladders/ropes/scaffolds. He could not reach overhead reaching [sic] but could frequently handle, finger, feel. He had to avoid hazards such as heights, moving machinery.
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6. Through the date last insured, the claimant was capable of performing past relevant work as a contractor (DOT 182.167-010, SVP 7, light exertion.), construction superintendent (DOT 182.167-026, SVP 7, light exertion). This work did not require the performance of work-related activities precluded by the claimant's residual functional capacity (20 CFR 404.1565).
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7. Alternatively, the claimant could do other work.
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8. The claimant was not been under a disability, as defined in the Social Security Act, at any time from November 17, 2009, through September 30, 2011, the date last insured (20 CFR 404.1520(f)).
Id. at 17-21.
Plaintiff's request for Appeals Council review was denied on March 12, 2015, leaving the ALJ's decision as the final decision of the Commissioner. Id. at 1-6.
II. LEGAL STANDARDS
The Commissioner's decision that a claimant is not disabled will be upheld if the findings of fact are supported by substantial evidence in the record and the proper legal standards were applied. Schneider v. Comm'r of the Soc. Sec. Admin., 223 F.3d 968, 973 (9th Cir. 2000); Morgan v. Comm'r of the Soc. Sec. Admin., 169 F.3d 595, 599 (9th Cir. 1999); Tackett v. Apfel, 180 F.3d 1094, 1097 (9th Cir. 1999).
The findings of the Commissioner as to any fact, if supported by substantial evidence, are conclusive. See Miller v. Heckler, 770 F.2d 845, 847 (9th Cir. 1985). Substantial evidence is more than a mere scintilla, but less than a preponderance. Saelee v. Chater, 94 F.3d 520, 521 (9th Cir. 1996). "`It means such evidence as a reasonable mind might accept as adequate to support a conclusion.'" Richardson v. Perales, 402 U.S. 389, 401 (1971) (quoting Consol. Edison Co. v. N.L.R.B., 305 U.S. 197, 229 (1938)).
"The ALJ is responsible for determining credibility, resolving conflicts in medical testimony, and resolving ambiguities." Edlund v. Massanari, 253 F.3d 1152, 1156 (9th Cir. 2001) (citations omitted). "Where the evidence is susceptible to more than one rational interpretation, one of which supports the ALJ's decision, the ALJ's conclusion must be upheld." Thomas v. Barnhart, 278 F.3d 947, 954 (9th Cir. 2002).
III. ANALYSIS
Plaintiff argues that the ALJ erred by (1) failing to provide any explanation for how he assessed plaintiff's RFC, and (2) not adequately explaining why plaintiff did not meet the listings at the third step of the sequential evaluation. ECF No. 16 at 4-6.
Turning to plaintiff's first argument, the ALJ determined that plaintiff maintained the RFC to perform light work, but with some postural, manipulative, and environmental limitations. AR 18. Plaintiff argues that it is "literally true" that the ALJ's "decision contains no explanation for its residual functional capacity" determination. ECF No. 16.
An individual's RFC is the most he can perform despite his limitations. 20 C.F.R. § 404.1545. In assessing a claimant's RFC, the ALJ is required to consider all medically determined impairments and relevant medical evidence. 20 C.F.R. 404.1545(a)(2)-(3). "The RFC assessment must include a narrative discussion describing how the evidence supports each conclusion, citing specific medical facts (e.g., laboratory findings) and nonmedical evidence (e.g., daily activities, observations)." SSR 69-8p.
The ALJ's decision includes a narrative discussion, but it is devoid of any explanation for how plaintiff's RFC was assessed. The narrative includes a brief summary of plaintiff's allegations of disabling pain, as well as an explanation for why the ALJ concluded that plaintiff's complaints were not fully credible. AR 19. However, it contains virtually no discussion of plaintiff's impairments or medical records. The only statement regarding plaintiff's medical records is that "[t]reatment notes repeatedly show that the claimant demonstrated physical examinations that showed claimant alert, well appearing, and in no significant distress." AR 19. This limited statement, however, provides no insight into how the ALJ determined that plaintiff could perform light work with some postural, manipulative, and environmental limitations. Nor does the ALJ's rejection of plaintiff's subjective complaint shed any light of how the ALJ arrived at plaintiff's RFC.2 The lack of discussion is surprising in a case with an administrative record spanning more than 600 pages of medical records. Id. at 235-861.3
The Commissioner attempts to compensate for the decision's shortcomings by citing to various portions of the record that might have been relied upon by the ALJ in making an RFC determination. However, in assessing whether the ALJ properly determined plaintiff's RFC determination, the court is limited to the explanation provided by the ALJ. See Bray v. Comm'r Soc. Sec. Admin., 554 F.3d 1219, 1225 (9th Cir. 2009) ("Long-standing principles of administrative law require [the court] to review the ALJ's decision based on the reasoning and factual findings offered by the ALJ—not post hoc rationalizations that attempt to intuit what the adjudicator may have been thinking."); Connett v. Barnhart, 340 F.3d 871, 874 (9th Cir. 2003) (a district court is "constrained to review the reasons the ALJ asserts"); Barbato v. Comm'r Soc. Sec. Admin., 923 F.Supp. 1273, 1276 n.2 ("If the decision on its face does not adequately explain how a conclusion was reached, that alone is grounds for remand. And that is so even if [the Administration] can offer proper post hoc explanations for such unexplained conclusions."). The decision fails to provide any explanation at all for how the RFC determination was reached, and therefore this matter must be remanded for further proceedings.4
IV. CONCLUSION
Accordingly, it is hereby ORDERED that:
1. Plaintiff's motion for summary judgment is granted;
2. The Commissioner's cross-motion for summary judgment is denied;
3. The matter is remanded for further proceedings consistent with this order; and
4. The Clerk is directed to enter judgment in plaintiff's favor.
