"I'm contracted to September 2019 and that will see me out," he told the BBC.
England finished at 180 for nine off 88.1 overs as Australia won by an innings and 123 runs.
All four of Australia's front-line bowlers finished with 20 or more wickets each for the series.
Usman Khawaja plundered a big century as Australia roasted England's bowlers on Saturday to open up a 133-run lead with two days to play
At the close, Smith was on 44 with Khawaja reaching his highest score of the series on 91 in Australia's 193 for two
Skipper Root again missed out on an elusive first century in the series as Aussies struck late on the opening day of last Test
Root and Malan stole the highlights on the opening day of the SCG Test
Woakes has taken 10 wickets at 49.5 in the four Tests and scored just 114 runs through seven innings batting number eight at an average of 16.28.
Left-armer Starc is the leading wicket-taker in the series with 19 despite only playing three Tests
PCB decides to resume PSL 2021 in June
South Africa name depleted squad for Pakistan T20Is owing to IPL constraints
'It was a joint decision' - Silverwood on Archer's omission from ODI side
Bravo century, Pollard blitz lift West Indies to series whitewash over Sri Lanka
Play and Win with 1st Cricingif Play League
PSL Schedule Live Streaming and PSL 5 Matches Details
Qualification scenarios: All teams in contention for a spot in the semi-finals
PCB appoints two-member panel to assess Covid-19 protocols during PSL 2021
PSL 2019 - PSL Schedule with all PSL 4 Matches and Schedule for all Franchises
Five cricket grounds with efficient drainage systems