More than 200 Kemsa employees reported to work physically on Friday after 19 months of working from home.
This comes a day after Health CS Susan Wafula directed new CEO Andrew Mulwa to ensure the employees returned to work.
She issued the order after a revelation that Kemsa has so far paid millions of shilling to the officers.
They had been directed to work from home in a 2021 executive order.
Through a letter dated April 14, former Medical Services Principal Secretary Peter Tum issued a similar call, instructing former Kemsa CEO Terry Ramadhani to recall the workers.
"Recall all the officers who are working from home. Fast-track the exit of employees of the authority serving on contract per the existing legal framework. This will address the problem of a bloated workforce," the PS directed.
The letter said the authority had drawn a caretaker team from wider public service to undertake the duties of the employees in question.
"Kemsa also recruited officers on short-term contracts to perform duties of the officers working from home," he added.
In the letter, Tum also revealed that the team working from home had taken Kemsa to court.
He called for an out-of-court settlement.
"Kemsa should negotiate with the officers who are in court for a possible out-of-court settlement. Undertake comprehensive business re-engineering to address some of the systemic challenges facing the authority," he said.