I've heard that all equipment purchased on grants and contracts is exempt from Indirect Cost. Is that true?

It depends on the budget. Please look at the indirect cost section of your budget profile in MyFD to find the 'Indirect Cost Actual Base' (it is the 3rd item under Indirect Cost). If you click on the title 'Indirect Cost Actual Base', it will take you to a glossary where it lists the possible codes and the descriptions. If your code does not specifically exclude equipment, then it is not exempt.