The EFFECTIVE date of your retirement will be the official date when you cease working in the Institutions. CIGNA asks “I confirm that I will be in active service for at least another 6 months”, you should answer affirmatively.
Up until 31/12/219 a medical questionnaire is still required by CIGNA. This will no longer be the case as from 01/01/2020 for those joining within 6 months of retirement (but there will be a waiting period of 2 years as opposed to 1 year at the moment).