The company International Health and Medical Services, or IHMS, says its contract to provide healthcare to refugees detained by Australia on Papua New Guinea's Manus Island ends today.
In a statement IHMS said it was maintaining "a core group of staff in Manus and Port Moresby to support the transition to a new health service provider".
The Australian government did not respond to questions about the end of the contract from RNZ Pacific but told SBS News it had "engaged a new health services provider".
It said "individuals will continue to have access to appropriate primary health services" but would not say who the new provider is.
IHMS said it had extended its contract to deliver health services at Australia's refugee detention centre on Nauru and to refugees residing in the Nauruan community.