Only 72 rental properties were within the reach of those on standard Housing Assistance Payment (HAP) payments, according to a survey of urban areas by the Simon Communities of Ireland.
The housing charity says supply is down by 9% on last year in a study of 16 areas and has expressed concern at the ending of the eviction moratorium.
The quarterly 'Locked Out' report found that there was only one property available for a single person on standard HAP, 50 for couples, eight for households with one child, and 13 for families with two children in March.
There were more properties available once extra discretionary payments, known as the homeless HAP, were paid.
The number of properties for single people on Homeless HAP rose to 84, there were 344 for couples, a further 545 was available for households with one child, and another 643 for those with two children.
Head of Policy and Communications at Simon Communities Wayne Stanley said "with the moratorium on evictions lifting at the end of last week, people can now be forced to leave their rental accommodation and that prospect is deeply concerning.
"This report sets out in stark terms the challenges that those who are at risk of homelessness face".
The number of properties available for couples saw a "significant" decrease of 15% since last December, according to the report.
It also found that the supply was "overwhelmingly" driven by Dublin with the vast majority of properties available for families with one or two children on Homeless HAP being situated in the capital.