Every medical procedure, from routine physicals to rarer surgeries has a (alpha?)numeric code associated with it. The codes are used by US health care providers to obtain payment/reimbursement from private insurers, Medicaid, Medicare and other government insurance. There are reference manuals with all of these codes, and I’m sure they’re online. There seems to always be a demand for coders. You will need some kind of training, since it is specialized. Ask the HR department of a hospital or other large provider if training is available. Otherwise, you might have to do a program.