EPIC provides independent advocacy and information for people who are living in or have exited State care.
This includes foster placements, high support and special care, as well as residential care settings.
Overall in 2017, EPIC responded to 589 cases, an increase from 500 in 2019.
EPIC said care placement remained the most prevalent issue for children and young people since it began compiling these reports nine years ago.
As many as 22% of the contacts received by the organisation were in relation to where the young person was placed and how they were cared for.
It said care issues ranged from, but were not restricted to, the child or young person being unhappy or uncomfortable in a foster placement, not having their needs met in residential care or having rules and restrictions placed on them that they were not happy with.
EPIC also said it saw a sizeable increase in the number of young people presenting to them as homeless, in particular young women who had left care and had nowhere to go.
In 2017, 16% of the young people it supported who had left care were homeless.
EPIC Chief Executive Terry Dignan said homelessness had many variations for young people who had left care.
He said they could include those in residential care placement, which is temporary accommodation, those who were "couch surfing"with friends, and those who were supported by homeless charities.
Another issue highlighted in the report is the lack of an aftercare plan or aftercare supports for people who had left or were about to leave care.
From September last year, every young person leaving care became legally entitled to have a care plan in place for them when exiting the system at the age of 18.
The plan is headed by a social worker and supports can include education, financial support and training.
Mr Dignan said while in theory he believed all structures and supports for people in care and leaving care were in place, he said there was a lack of consistency nationally as to how policy and entitlements were applied.
In his experience, he said, for those to receive all necessary supports and entitlements, it could come down to what area the child or young person was being cared for in.
Tusla, under the instruction of the Minister for Children and Youth Affairs, is the State body tasked with providing and supporting care services for children and young people.
In a statement issued to RTÉ News it said it was committed to maintaining support to care leavers through the delivery of programmes that enable young people to adequately prepare for leaving care.
It said it was currently increasing the number of staff employed in aftercare services and said additional supports such as drop-in support services, practical living supports, and accommodation were all being developed.
Reporting Ciara NíBhroin
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