The let-down comes less than a month after he withdrew from speaking at the NHS Alliance conference, and echoes Lord Darzi's last-minute withdrawal last year. Health minister Mike O'Brien will take Mr Burnham's place.
A DoH spokeswoman denied the decision was a snub. 'Andy Burnham is going to the US for the launch of the Commonwealth Fund report, which is an event attended by secretaries of state every year.
'He will be promoting the work of UK GPs and the wider NHS in providing high-quality services on an international stage. He has recorded a message to the conference, thanking GPs for their hard work.
'The department and its ministerial team take the RCGP conference seriously and are pleased that Mike O'Brien is attending. This will be a great opportunity for him to meet GPs and discuss the issues that are affecting them.'