It had to agree to new austerity measures "to broaden tax bases and eliminate wasteful spending" to get approval for a desperately needed financial support package.
As part of the package, the IMF gave nod to a $235.6 million (Sh28.3 billion) disbursement to Kenya two months ago.
This is after it approved a third review of the country's Extended Credit Facility and Extended Fund Facility arrangements.
The disbursement was to be deployed for budget support and brought such payouts to $1.208 billion (Sh145.27 billion) under the 38-month arrangements, which were worth $2.34 billion (Sh281.41 billion) when they were approved in April 2021.
Once in office from next week, Dr Ruto will have to steer an economy battered by the Covid-19 pandemic, rising food and fuel prices spurred by the war in Ukraine, the worst drought in four decades and soaring public debt levels.
"IMF staff urges steadfast commitment to prudent policies and advancing essential reforms to maintain macroeconomic stability and safeguard Kenya's medium-term prospects," the IMF said.
The IMF has in the past called for end to fuel subsidies such as on maize and fuel which President Kenyatta turned to cushion Kenyans amid the surge in cost of living.
"This conversation...about creating jobs, cost of living, dealing with debt, making sure that we have sufficient revenues," Dr Ruto said ahead of the polls as he hinted he will go big on social spending.
The IMF in the past urged for better tax collection by the State as well as reforms in the loss-making State-owned companies such as Kenya Airways and Kenya Power.
The IMF believes these organisations are overstaffed and that in some cases employees are overpaid.