My father passed away in February of this year. The official cause was pneumonia; however, the secondary cause was emphysema and COPD.

I think you are speculating when you conclude that a referral to a cardiologist or a pulmonary physician would have resulted in a better quality of life for your father.  A good internist can often provide palliative care that is comparable to the care provided by a specialist. Beyond that, because your father already had a pre-existing condition that contributed to his problems, the damages in the case will be the "difference" that the referral would have made on your father's overall condition. This is going to raise issues about whether or not the case is financially viable. That aside, if you do want to investigate a medical malpractice case, you should contact a local medical malpractice attorney (one in your state).  They take these cases on a contingency basis which means you only have to pay if you succeed.  Additionally, initial consultations are usually free. You can use the "Find a Lawyer" service through this website to research medical malpractice attorneys.  Then, visit each attorney's website and look for a firm that has a record of successful verdicts.  Below are some articles you may find helpful.  They are written for a New Jersey audience (where I practice) but the ideas discussed in these articles usually apply in most other jurisdictions as well. Click here for an article that discusses the three main questions I ask when deciding whether to investigate a potential medical malpractice case. Please note that by attempting to answer your question, I am not acting as your attorney. I will do nothing further to protect or preserve your interests in the absence of any additional discussion with you about this matter. John Ratkowitz, Esq. Starr, Gern, Davison & Rubin, P.C. 105 Eisenhower Parkway Roseland, NJ 07068 Office: (973) 830-8441 Cell: (732) 616-6278 Fax: (973) 226-0031 Email: jratkowitz@starrgern.com  Skype: john_ratkowitz Web: www.starrgern.com.