There is no difference ... any change in expected annual income reported to the ACA in order to qualify for an advance premium credit needs to be reported asap so the advance can be adjusted or eleminated for the rest of the year however this will not change the excess paid earlier in the year ... that is reconciled on the form 8962 when you file your return. Sadly the law was not written to take into consideration events that happen as the year goes on so you could have no income in January thru November but win the lottery in Dec which would negate the entire advance credit and you would have to pay it all back.
