The report released Friday by Equality Illinois comes a year after Illinois enacted civil unions, which grant same-sex couples many of the same rights and protections as marriage but not all.
The group's report is based on about 225 online survey responses from same-sex couples.
The report says more than eight out of 10 couples reported difficulty in filing joint taxes and that financial advisers were "ill-equipped" to prepare taxes for civil union couples.
More than half of those who responded had trouble getting health insurance for civil union partners. Others reported issues with visiting civil union partners in the hospital.
Copyright 2012 The Associated Press.