Cwmbran-based Expanding Horizons secured the homes following its takeover of Enable Care Services (South Wales) Ltd.
The acquisition was funded by a £3.25 million investment from NatWest.
Ellis Jenkins, director at Expanding Horizons, said: “At Expanding Horizons, we care deeply about the quality of care our service users receive.
“We seek to not only support individuals but empower them to be the best versions of themselves.
“The fact that so many people in Wales are living with disabilities and severe mental illness underscores the critical need for tailored support which helps them gain or rebuild their independence.
“Residents of South Wales deserve the highest quality of care, and we are thrilled to announce the acquisition of Enable Care Services as we continue to grow and expand our network.
“NatWest has been exceptional throughout the process, demonstrating a deep understanding of our industry and our goals and we are incredibly grateful for their support.”
The deal includes two care homes in Cwmbran and one in Argoed.
Expanding Horizons provides personalised support for people with learning disabilities and severe mental illnesses.
The company marks its 20th anniversary this year.
Part of the funding will go towards the acquisition, while the remainder will support refinancing and infrastructure improvements to ensure regulatory compliance.
The expansion is aimed at meeting the rising demand for residential and supported living services across South Wales.
According to Public Health Network Cymru, around 900,000 people in Wales live with a disability.
This represents 27 per cent of the population, compared to the UK average of 22 per cent.
Neil Williams, senior relationship manager at NatWest, said: “The work that Expanding Horizons does is absolutely invaluable to its service users and is the exact sort of community benefit that we look to support at NatWest.
“We look forward to continuing our partnership and are excited to witness Expanding Horizon’s continued growth and evolution.”
Expanding Horizons said the acquisition will improve its ability to deliver high-quality care across the region.
The company currently operates a portfolio of care homes and supported living services in South Wales.