I need to file a medical malpractice lawsuit in Alabama, because the hospital did not diagnose my spinal cord injury.

It depends on how the language is described in your state's statute.  Interpreting the statute regarding a limitations period is very dependent on the specific facts of each case, and thus, I do not feel I have enough information to answer your question fully. To be safe, you should probably assume it is when you were last seen at the hospital and misdiagnosed as this is when the "harm" occurred.  I do recommend that you seek the advice of an attorney on this.  Medical malpractice suits are extremely difficult and have lots of requirements, like the hiring of an expert witness (sometimes before a suit is even filed) and I do not recommend attempting to pursue one pro se (without an attorney).  In addition, these cases are very expensive.  The hiring of an expert witness can cost thousands of dollars, plus there are numerous other expenses.  Most attorneys who handle malpractice cases will do so on a contigency fee basis, meaning that they do not get paid unless you win your case, and if  you don't win your case, then you do not owe the attorney anything.  Best of luck! NOTE: This response is general in nature and should be considered legal advice.  No attorney-relationship exists or is formed by this information.