Is it necessary to specify the reason for making up missed fasts – such as menstruation or travel – or is the intention to make up for Ramadan sufficient?

For making up missed Ramadan fasts, the intention to make up the fast is sufficient. It is not necessary to specify the reason for making up the fast nor the specific day being made up, because it is all of one type. Similarly, the jurists have not stipulated the need to specify the reason for making up the fast along with the intention to make it up.