Fowler's Modern English Usage has
Composite adjectives when used attributively are usually given hyphens, mostly with good reason.
but later continues with
... combinations of two or more words needing hyphens when used attributively can usually do without them as predicates.
which seems to me to say that you should use the hyphen in a sentence like
The bank manager contacted me about the charged-off loan for my car.
but that you could omit them if the adjective were separated from the noun, like this.
The bank manager told me that the loan for my car had been charged off.