Here is a summarized list of the requirements necessary to be eligible for an instrument rating. The list is summarized from the Federal Aviation Regulations. Please refer always to the FAR's if your particular situation warrants exceptions due to licenses and ratings that you already hold.
To be eligible for an instrument rating:
1. Hold at least a current private pilot license with an airplane.
2. Be able to read, speak, and write the English language fluently.
3. Hold a current Airman Medical Certificate.
4. Receive and log ground training from an authorized instructor or accomplish a home-study course appropriate to the instrument rating.
5. Pass the knowledge exam with a 70% or higher.
6. Receive flight training from an authorized instructor and receive the appropriate endorsements to take your practical test and knowledge test.
7. Log the following hours:
(a) At least 50 hours of cross-country flight time as pilot in command, of which at least 10 hours must be in airplanes for an instrument -- airplane rating; and
(b) A total of 40 hours of actual or simulated instrument time on the areas of operation of this section, to include--
(i) At least 15 hours of instrument flight training from an authorized instructor in the aircraft category for which the instrument rating is sought;
(ii) At least 3 hours of instrument training that is appropriate to the instrument rating sought from an authorized instructor in preparation for the practical test within the 60 days preceding the date of the test.
For a more complete breakdown of how your flight hours are spent during your training, please download the PDF file below.