A common source of confusion among claimants is when and if the SSA is responsible for obtaining copies of their medical records. Generally, the Social Security Administration can provide you with assistance in obtain copies of your records. However, this duty applies primarily to the early stages of a case. So, at the Initial and Reconsideration stages, the Disability Determination Service (DDS) will usually request copies of records at their expense.
Unfortunately, even though DDS is supposed to help obtain records at this level, there are common issues that arise. First, DDS will usually only request records for the past two years. This often prevents consideration of pertinent evidence. If you have older records that might be useful in the case, it is usually worthwhile to get these on your own.
Additionally, though DDS will request and pay for records, they are often not very diligent in following up on records requests. It is useful for you to keep track of where DDS is sending its records requests and to verify with your providers that records have been sent.
Finally, once the case has been appealed to the hearings level, it is up to the ALJ to decide whether or not to assist a claimant in requesting records. In my experience, the Judges almost always view it solely as the responsibility of the claimant to obtain these records. Therefore, at the hearings level you need to obtain and submit your records well in advance of your hearing.