The Pro-Pilot Card is awarded to any instrument pilot who can demonstrate proficiency at the Airline Transport Pilot (ATP) level. It's differs from an Instrument Proficiency Check (IPC) in that the pilot must meet the more rigorous standards specified in the FAA ATP Airman Certification Standards. It's valid for 6-months following the evaluation and is usually completed twice a year. Insurance underwriters may provide additional incentives for demonstrating proficiency at this level.
You may request a card during any training event. It may involve additional evaluation time and expense depending on your level of proficiency.