Are there redemption penalties on US mortgages for paying off early?

No...not if the mortgage was underwritten by any branch of the U.S. Federal Government, like FHA, FannieMae, or FreddieMac. No FDIC insured bank is allowed to make that type of real estate loan because it is not allowed within FDIC guidelines.

If you borrowed money from a individual or a "hard money" lender, most likely there will be a pre-payment penalty.

Many loans had early pay off penalties. Almost all loans included this until around 2000 at the start of the housing boom.

- read your mortgage to determine if yours included this.

Look at the Truth-In-Lending Statement that came with your loan docs. There is an obvious checkmark indicating whether or not your loan has a prepayment penalty.

Only if they are specified in the original mortgage note. Smart people don't get those types of mortgages, but they do exist.

The only way to know is to read the contract that you signed.

Usually no, but you'd have to read your specific loan docs to be sure.