About domestic partnerships
A registered domestic partnership is "a civil contract entered into between two individuals of the same sex who are at least 18 years of age, who are otherwise capable and at least one of whom is a resident of Oregon." Oregon doesn't recognize civil unions or domestic partnerships certified in other states.
Registered domestic partners (RDP) in Oregon receive the same tax treatment as married individuals. Just like a married couple, you and your partner may file jointly or separately. As an RDP, you can't file using the single filing status on your Oregon return.
By filing jointly, you may be able to take advantage of additional tax benefits, but you're also subject to additional tax responsibilities. For example, like married joint filers, RDPs filing jointly are held jointly and severally liable for their entire tax debt.
The federal government doesn't recognize domestic partnerships as married individuals for federal tax purposes.
Filing your Oregon Tax Return
Since the federal government doesn't recognize RDPs for tax purposes, you'll need to complete two federal returns. If you were an RDP under Oregon law on the last day of the tax year (generally December 31) or if you were an RDP during the year and your partner died and you didn't enter into a new RDP or marry during the year, follow these directions when completing your return:
Use the single or head-of-household filing status on your actual federal return and send it to the IRS.
Use the married filing jointly or married filing separately status on your second "as-if" federal return and attach this to your Oregon return only. Don't submit this form to the IRS.
The filing status on your Oregon return must match the filing status on your "as-if" federal return. Remember to also complete alternate versions of all required federal schedules and include them with your Oregon return. Don't submit these alternate forms to the IRS. If you and your partner are
filing separately, you must each submit an "as-if" federal married filing separately return with your Oregon return and mark the checkbox "calculated using 'as-if' federal return."
If you're filing with tax preparation software, ensure that the software allows you to file as an RDP. If you use a professional tax preparer, be sure to ask if their software supports RDP filings. File the federal return and then complete the "as-if" federal return. Use the "as-if" federal return to complete the Oregon return. When e-filing for Oregon, you must submit a "state only" submission.
Deductions, Exclusions, and Credits
Federal law limits certain deductions, exclusions, and credits based on filing status and/or federal adjusted gross income (AGI). As an RDP, you are required to use either the married filing jointly or married filing separately status on your Oregon return. Learn more about deductions, exclusions, and credits in Publication OR-17 to see how your filing status affects what you can claim on your return.