Do I need a federal or state extension if I am due a refund?

I will not be able to prepare and submit my taxes next year until after April 15th, most likely not until May. I am expecting a refund from both the state and federal income taxes. From what I can find, I can simply just file my federal income tax return without needing an extension without any penalty against my refund? Is this the same for New York State income state taxes? If I file both the NYS and Federal income taxes in the month of May and I am getting a refund from both the State and Federal taxes, do I need an extension and if not, will there be any penalty which would decrease the amount of my refund for either? For example, if I am expecting a refund of $1500 from the Federal taxes and a refund of $500 from the NY State taxes, will I still see the $1500 from the Federal and $500 from NYS if I file my taxes in May or June?