The FTSE 250 firm expects annual revenues of £3bn and underlying trading profit of around £150m, meeting its improved full-year forecast outlined in May.
The trading update comes as the firm announced a £600m deal to provide Barts Health NHS Trust with facility management services for the next seven to 10 years.
Last week, rival outsourcing firm Mitie swung to a £100.4m half-year loss and issued a profit warning as it felt the force of increased economic uncertainty and higher staffing costs.
Serco group chief executive Rupert Soames said: "2016 has seen a lot of hard work and the successful resolution of a number of commercial issues which will result in underlying trading profit materially better than we expected at the start of the year, and which will be in line with the increased guidance we gave in August."
For 2017, Serco expects revenues to hit £3.1bn and underlying trading profit of between £65m and £70m.
"Our view of the underlying outlook for 2017 remains unchanged, which means that we are continuing to make good progress with the execution of our strategy for the long-term turnaround of Serco," he added.
Serco's financial performance improved in the first half of the year after it ironed out a number of "commercial issues", including a better-than-expected final settlement on its Northern Rail contract.
Its overseas businesses also enjoyed a boost from sterling's 18% drop against the US dollar since the Brexit vote.
The brighter outlook follows a torrid couple of years for the firm, which has seen it issue a string of profit warnings and admit in 2013 to charging the Government for tagging criminals who were dead or non-existent.