A 3rd Class Medical is required for all private pilots in the US. Student pilots need a 3rd class medical certificate prior to solo. Prior to 4/1/16, student pilots would get a combination student pilot/medical certificate; now you must apply separately for a student pilot certificate. I recommend getting your medical after you’ve had a few flight lessons, but well before your first solo flight. If you have a pre-solo knowledge test to work on, then it is definitely time to get your medical certificate. You must carry the medical certificate with you when you are pilot in command (including solo). If you are under the age of 40, your medical will be valid for 60 calendar months; otherwise, it is valid for 24 calendar months [e.g., get your medical on 1/7/15 and it is good until 1/31/17].
2nd Class medical certificates are required for commercial pilots and 1st class medical certificates are required for airline pilots. If you think you might need a 2nd class medical in the near future, you can apply for a 2nd class instead of a 3rd class; the differences in the medical tests are very slight (an additional eye test and the need for 20/20 vs 20/40 vision)
Finding a doctor
FAA medical examinations are performed by Aviation Medical Examiners (AMEs). AMEs are doctors who have been approved by the FAA. An appointment is necessary. The current rate is around $85 (Aug 2015). A reasonably local option is John T Phillipp (Glendora); his hours for examinations are very flexible. I used Dr. Phillipp for my most recent medical. Several pilots I know have had very good luck with him for difficult medical cases and he has been very willing to discuss any possible issues over the phone prior to your application or appointment. Dr Riffenburgh in Pasadena has retired.
What is involved?
A 3rd class medical is meant to ensure you are healthy enough to be a pilot. If you have no existing medical conditions and are not on any medications, it is usually a straightforward process. If you have a medical condition, or are on any medications, then I recommend some research prior to going for the examination. See detailed information on the requirements. If unsure about your ability to pass the medical test, don’t apply – get a consultation with an AME first to determine what can be done and any tests and documentation that would be needed.
As of 2012, the FAA has moved to an online medical application, MedExpress. Be careful in filling out the online application and refer to the online help. You should submit the application prior to your appointment and print the form out and bring to your appointment. At the doctor’s office, you’ll also be asked to give a urine sample (diabetes screening). The doctor will look over your application and make sure it is filled out fully and properly. The examination will include an eye test, a test of your reflexes, listening to your lungs, checking your heart rate and blood pressure, and the general poking and prodding you expect during most physical examinations.
If all goes well, the doctor (or his assistant) will prepare your medical certificate. You’ll generally be done in much less than an hour.