IRS reference code 1091 signifies a full or partial "offset" of your refund. An offset means IRS is taking some/all of your refund due to certain debts you may have (Child Support, Certain Federal and State Debts, and Unemployment Compensation Debts).
Here is a link to the IRS page discussing the various
aspects of offsets: https://www.irs.gov/taxtopics/tc203.html. Note the telephone contact number which you can call for information. If you are subject to an offset, you should expect to receive a notification letter from IRS shortly.
