MEMORANDUM OPINION AND ORDER OF COURT
TERRENCE F. McVERRY, District Judge.
John Leist ("Plaintiff") brings this action pursuant to 42 U.S.C. § 405(g), seeking review of the final determination of the Commissioner of Social Security ("Defendant" or "Commissioner") denying his application for Disability Insurance Benefits ("DIB") and Supplemental Security Income ("SSI") under Titles II and XVI of the Social Security Act, 42 U.S.C. §§ 401-433, 1381-1383f ("Act"). This matter comes before the court on cross motions for summary judgment. (ECF Nos. 12, 14). The record has been developed at the administrative level. For the following reasons, the decision of the ALJ will be VACATED, and the case REMANDED.
II. PROCEDURAL HISTORY
Plaintiff filed for DIB and SSI with the Social Security Administration on February 17, 2010, claiming a disability onset date of September 30, 2009. (R. at 102-10). Plaintiff's alleged inability to work resulted from limitations stemming from colitis and Crohn's disease. (R. at 132). Plaintiff was initially denied benefits on April 15, 2010. (R. at 65-73). A hearing was scheduled for March 28, 2011, and Plaintiff appeared to testify, represented by counsel. (R. at 29-54). A vocational expert also testified. (R. at 29-54). The Administrative Law Judge ("ALJ") issued her decision denying benefits to Plaintiff on April 14, 2011. (R. at 7-18). Plaintiff filed a request for review of the ALJ's decision by the Appeals Council, which request was denied on July 24, 2012, thereby making the decision of the ALJ the final decision of the Commissioner. (R. at 1-4).
Plaintiff filed his Complaint in this court on September 11, 2012. (ECF No. 3). Defendant filed an Answer on November 23, 2012. (ECF No. 8). Cross motions for summary judgment followed. The matter has been fully briefed. (ECF Nos. 13, 15, 16).
III. STATEMENT OF THE CASE
A. General Background
Plaintiff was born on September 8, 1961, was forty eight years of age at the time of his application for benefits, and was forty nine years of age at the time of the ALJ's decision. (R. at 116). Plaintiff obtained a GED, and thereafter completed vocational training to become a diesel mechanic. (R. at 133-34). Prior to his alleged disability onset, Plaintiff worked as an installer/laborer for a plumbing and remodeling company. (R. at 134). Plaintiff was unmarried, but had an adult son. (R. at 37). He lived independently, subsisted on cash assistance and food stamps, and received medical benefits through the state. (R. at 38, 141).
B. Treatment History
Plaintiff was first evaluated by doctors at Lawrenceville Family Health in Pittsburgh, Pennsylvania on October 20, 2009. (R. at 217). Plaintiff was there for exacerbation of his Crohn's disease, which had not bothered him until recently. (R. at 217). Plaintiff had not seen a gastroenterologist since he was a teenager. (R. at 217). Plaintiff stated that he had been losing a significant amount of weight, and suffered from intestinal gas and pain, and had bloody diarrhea. (R. at 217-18). Plaintiff was referred for a colonoscopy. (R. at 218).
Plaintiff appeared again at Lawrenceville Family Health for continued Crohn's-related complaints on October 16, 2009. (R. at 222). He informed the doctor that he had not experienced a flare-up for four years. (R. at 222). He explained that the flare-ups usually last for a month, and would calm down if he pays attention to what he eats. (R. at 222). Plaintiff also noted to have recently lost his job due to longstanding issues with his employer's son. (R. at 222). Plaintiff was again referred for a colonoscopy. (R. at 223).
On January 5, 2010, Arthur Barrie, M.D. performed a colonoscopy and digital rectal examination of Plaintiff. (R. at 197). Dr. Barrie found that Plaintiff suffered from active Crohn's colitis complicated by ileocecal valve stenosis, ascending colon pseudopolyps, descending colon inflammation with stenosis, and rectal pseudopolyps with a possible rectal fistula. (R. at 197).
On January 22, 2010, gastrointestinal surgeon Andrew R. Watson, M.D. drained a perirectal abscess from Plaintiff. (R. at 169-70). The procedure was without complications, and Plaintiff was noted to be in good condition. (R. at 169-70).
On January 25, 2010, Dr. Barrie prescribed Plaintiff azathioprine and infliximab for treatment of moderately sever ileocolonic Crohn's disease complicated by a perianal fistula and abscess. (R. at 245). Plaintiff was recommended for aggressive medical management. (R. at 245). Plaintiff was seen again by Dr. Barrie on March 1, 2010. (R. at 244). Plaintiff had not been taking his prescribed medication for Crohn's management due to "self-reported ...