The Rehab Group has warned it will have to give the HSE 12 months' notice of termination of its entire care service due to funding problems.
The charity said vital services for 3,000 adults and children with disabilities are under threat, due to ongoing significant underfunding.
Representatives of the group met with Health Minister Simon Harris over their concerns this evening.
Following the meeting, Rehab Group have said it will now delay the issuing of the notification to the HSE in order to engage in a week-long process of intense discussion with the HSE in a bid to seek resolution.
Rehab will meet Minister Harris again on May 15 to identify a solution which will safeguard critical services for the 3000 people in its care and its1,500 staff.
In a statement, Rehab Group said that that it will continue to fight for the funding needed to safeguard the services critical to the people it serves.
Jimmy Tolan, the chairman of the Rehab Group's board of directors, said: "This is an unprecedented decision, one we never imagined we would have to make. During the last two years, we have done everything in our power to engage with the HSE to secure adequate funding for these services.
"Now Rehab is no longer in a position to continue to fund the significant losses incurred in providing these services and is in an extremely difficult position where it has no other option but to issue 12 months' notice of termination to the HSE."
Mr Tolan warned that financial concerns are a "sector-wide issue", and it's their "profound hope" that the services can continue.
However, he added: "This situation can be reversed, the care services could be saved but only if we are provided with urgent additional funding to ensure that these services continue."
According to the charity, the funding problems centre around its RehabCare - noting that the group's other services continue to operate as normal.