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 Supplemental Security Income ("SSI") under Title XVI 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 November 8, 2007, through the date of the final administrative decision. (Dkt. No. 16.) The Commissioner filed an opposition to plaintiff's motion and a cross-motion for summary judgment. (Dkt. No. 21.) Plaintiff filed a reply brief. (Dkt. No. 22.) For the reasons that follow, the court will grant plaintiff's motion for summary judgment in part, deny the Commissioner's cross-motion for summary judgment, and remand the case for further proceedings under sentence four of 42 U.S.C. § 405(g).
Plaintiff was born on May 25, 1964, has a ninth grade education earned mostly in special education classes, and essentially has no past work history.*fn2 (Administrative Transcript ("AT") 15, 34, 114-34.) On November 8, 2007, plaintiff applied for SSI, alleging that she was unable to work as of June 29, 1982,*fn3 primarily due to depression, diabetes, asthma, seizures, and high blood pressure. (AT 17, 116.) On April 30, 2008, the Commissioner determined that plaintiff was not disabled. (AT 17, 68-72.) Upon plaintiff's request for reconsideration, the determination was affirmed on August 26, 2008. (AT 17, 76-80.) Subsequently, plaintiff requested a hearing before an administrative law judge ("ALJ"), which took place on September 14, 2009. (AT 17, 43, 82-84.)
In a decision dated January 22, 2010, the ALJ determined that plaintiff had not been under a disability, as defined in the Act, since November 8, 2007, the date that her application was filed. (AT 15-37.) The ALJ's decision became the final decision of the Commissioner when the Appeals Council denied plaintiff's request for review on February 25, 2011. (AT 1-5.) In the course of its review, the Appeals Council received additional evidence, which was made part of the record. (AT 5.) Subsequently, plaintiff filed this action in federal district court on April 1, 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 evaluated the opinion evidence concerning plaintiff's mental health impairments and functional limitations;*fn4 (2) whether the Appeals Council erred by refusing to remand the case to the ALJ based on the additional evidence submitted after the ALJ's decision; and (3) whether the ALJ improperly discredited plaintiff's testimony regarding her symptoms and 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 SSI pursuant to the Commissioner's standard five-step analytical framework.*fn5 At the first step, the ALJ concluded that plaintiff had not engaged in substantial gainful activity since November 8, 2007, plaintiff's application date. (AT 20.) At step two, the ALJ determined that plaintiff had the following severe impairments: major depressive disorder, posttraumatic stress disorder with history of polysubstance abuse in current remission, seizure disorder, asthma, and diabetes mellitus. (AT 20.) 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 23.)
Before proceeding to step four, the ALJ assessed plaintiff's RFC as follows:
[T]he claimant has the residual functional capacity to perform medium work as defined in 20 CFR 416.967(c) except the claimant retains the residual functional capacity for substantially all of the full range of medium exertional work, reduced by significant postural limitations that preclude the claimant from all climbing of ropes, ladders and scaffolds and that precludes more than frequent balancing, climbing of ramps/stairs, crawling, crouching, kneeling and stooping, significant environmental limitations that preclude working around even moderate exposure to fumes, smoke, gases and other irritants, and that preclude working with any hazards, including heights and dangerous machinery, and significant mental limitations that preclude interacting with the public on more than an occasional basis. However, she can understand, remember, and carry out simple one to two step job instructions; she is able to maintain concentration, persistence and pace for simple job tasks and is able to interact appropriately with supervisors and co-workers. (AT 29-30.)
At step four, the ALJ found that plaintiff had no past relevant work. (AT 34.) Finally, at step five, the ALJ noted that plaintiff was 43 years old on the date of her application for SSI, had a "limited or less" education, but was able to communicate in English. (AT 34.) She further concluded that transferability of job skills was not an issue, because plaintiff did not have past relevant work. (AT 35.) The ALJ found that, upon consideration of plaintiff's age, education, work experience, and residual functional capacity, "there are jobs that exist in significant numbers in the national economy" that plaintiff could perform. (AT 35.) The ALJ relied on the testimony of a vocational expert ("VE"), who testified that an individual with plaintiff's RFC could perform the following representative occupations: (1) warehouse worker, medium, unskilled, with 75,000 jobs in California; (2) hand packager, medium, unskilled, with 14,000 jobs in California; (3) office helper, light, unskilled, with 16,000 jobs in California; and (4) mail clerk, light, unskilled, with 10,000 jobs in California. (AT 35-36.) Accordingly, the ALJ concluded that plaintiff had not been under a disability, as defined in the Act, since November 8, 2007, the date that plaintiff's application for SSI was filed. (AT 36.)
B. Plaintiff's Substantive Challenges to the Commissioner's Determinations
1. Whether the ALJ improperly evaluated the opinion evidence concerning plaintiff's mental health impairments and functional limitations
In this case, there is no dispute that plaintiff suffers from severe mental impairments, including major recurrent depression with psychotic features, post-traumatic stress disorder, and polysubstance dependence in remission, attributable in part to sexual and physical abuse as a child by her father. (AT 17, 20, 26, 252.) The ALJ further noted that plaintiff had a ninth grade education earned mostly in special education classes and had essentially no work history. (AT 15.) It also appears that plaintiff received SSI benefits from the age of 17 based on asthma, a seizure disorder, and mental retardation measured by testing at that time, but that her disability was determined to have ceased for ...