The opinion of the court was delivered by: Kendall J. Newman United States Magistrate Judge
Plaintiff seeks judicial review of a final decision of the Commissioner of Social Security ("Commissioner") denying plaintiff's application for Disability Insurance Benefits ("DIB") under Title II of the Social Security Act ("Act").*fn1 In her motion for summary judgment, plaintiff principally contends that the Commissioner erred by finding that plaintiff was not disabled from May 31, 2007, through the date of the final administrative decision. (Dkt. No. 13.) The Commissioner filed an opposition to plaintiff's motion and a cross-motion for summary judgment. (Dkt. No. 16.) For the reasons that follow, the court grants plaintiff's motion for summary judgment in part, denies the Commissioner's cross-motion for summary judgment, and remands the case for further proceedings under sentence four of 42 U.S.C. § 405(g).
Plaintiff was born on January 5, 1967, has attended four or more years of college, and previously worked as a paralegal and legal/office assistant.*fn2 (Administrative Transcript ("AT") 78-79, 84, 88, 143, 173, 175.) On January 15, 2009, plaintiff applied for DIB,*fn3 alleging that she was unable to work as of May 31, 2007, primarily due to back/neck injuries, fibromyalgia, chronic pain and fatigue, and depression. (AT 11, 84, 161, 167.) On July 22, 2009, the Commissioner determined that plaintiff was not disabled. (AT 11, 84.) Upon plaintiff's request for reconsideration, the determination was affirmed on February 16, 2010. (AT 11, 88.) Subsequently, plaintiff requested a hearing before an administrative law judge ("ALJ"), which took place on October 20, 2010. (AT 11, 57, 113.)
In a decision dated December 21, 2010, the ALJ determined that plaintiff had not been under a disability, as defined in the Act, from May 31, 2007, through the date of that decision. (AT 11-20.) The ALJ's decision became the final decision of the Commissioner when the Appeals Council denied plaintiff's request for review on July 29, 2011. (AT 1-6.) Thereafter, plaintiff filed this action in federal district court on September 27, 2011, to obtain judicial review of the Commissioner's final decision. (Dkt. No. 1.)
Plaintiff has raised the following issues: (1) whether the ALJ improperly failed to rule on plaintiff's motion to reopen a prior application; (2) whether the ALJ improperly rejected the opinions of plaintiff's treating physician and the consultative psychiatric examiner; and (3) whether the ALJ improperly discounted the testimony of plaintiff and third parties as to the nature and extent of plaintiff's functional limitations.
The court reviews the Commissioner's decision to determine whether (1) it is based on proper legal standards pursuant to 42 U.S.C. § 405(g), and (2) substantial evidence in the record as a whole supports it. Tackett v. Apfel, 180 F.3d 1094, 1097 (9th Cir. 1999). Substantial evidence is more than a mere scintilla, but less than a preponderance. Connett v. Barnhart, 340 F.3d 871, 873 (9th Cir. 2003) (citation omitted). It means "such relevant evidence as a reasonable mind might accept as adequate to support a conclusion." Orn v. Astrue, 495 F.3d 625, 630 (9th Cir. 2007), quoting Burch v. Barnhart, 400 F.3d 676, 679 (9th Cir. 2005). "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). "The court will uphold the ALJ's conclusion when the evidence is susceptible to more than one rational interpretation." Tommasetti v. Astrue, 533 F.3d 1035, 1038 (9th Cir. 2008).
A. Summary of the ALJ's Findings
The ALJ evaluated plaintiff's entitlement to DIB pursuant to the Commissioner's standard five-step analytical framework.*fn4 As an initial matter, the ALJ found that plaintiff remained insured for purposes of DIB through September 30, 2012. (AT 13.) At the first step, the ALJ concluded that plaintiff had not engaged in substantial gainful activity since May 31, 2007, plaintiff's alleged disability onset date. (Id.) At step two, the ALJ determined that plaintiff had the following severe impairments: "nonspecific generalized myofascial discomfort, fibromyalgia, multiple joint pain to the back and neck, status post automobile accidence [sic], chronic pain syndrome, depression and substance abuse." (Id.) However, at step three, the ALJ determined that plaintiff did not have an impairment or combination of impairments that meet or medically equal an impairment listed in 20 C.F.R. Part 404, Subpart P, Appendix 1. (AT 16.)
Before proceeding to step four, the ALJ assessed plaintiff's RFC as follows: "[T]he undersigned finds that the claimant has the residual functional capacity to perform sedentary work as defined in 20 CFR 404.1567(a) except the claimant can perform detailed but not complex tasks; alternatively, she can understand, remember and carry out simple instructions in a nonpublic setting." (AT 17.)
At step four, the ALJ found that plaintiff was capable of performing her past relevant work as an office assistant. (AT 16.) It is unclear how the ALJ reached this conclusion, because the vocational expert ("VE") testified that, in light of plaintiff's assessed RFC, plaintiff was unable to perform her past work. (AT 79.) Nevertheless, the ALJ, in the alternative, proceeded to step five and determined, based on the VE's testimony, that there were a significant number of other jobs in the economy that plaintiff could perform. (AT 19.) These jobs included document preparer (with 200 jobs in the regional economy, 4,000 jobs in California, and 30,000 jobs in the national economy); nut sorter (with 20 jobs in the regional economy, 1,000 jobs in ...