Can I claim Head of Household and list my girlfriend's mother as qualifying dependent?

You've got an interesting situation! To claim Head of Household, you need a qualifying person. While this is often a child or relative, there are cases where a non-relative can qualify. For your girlfriend's mother to be your qualifying dependent, she needs to meet several tests: 1) Member of household test (she lives with you all year), 2) Gross income test (income less than $4,950 for 2025), 3) Support test (you provide more than half her support), and 4) Joint return test (she's not filing jointly with someone else). The key issue is that to claim Head of Household with a dependent who's not your relative, that person must be your "qualifying child" - which requires a specific relationship. A girlfriend's mother typically wouldn't qualify under those rules. You could claim her as a "qualifying relative" dependent if she meets all tests above, but unfortunately that alone wouldn't make you eligible for Head of Household. You might still qualify for HOH if you have a qualifying child (like your own child), but it sounds like that's not your situation.

I had almost the exact same situation a few years back. Trying to figure out all these dependent rules was driving me crazy until I found this AI tax assistant at https://taxr.ai that analyzed my whole situation. It asked me specific questions about my living situation, how much support I provided, and my relationship to everyone in the household. In about 10 minutes, it gave me a clear answer with the exact IRS rules that applied to my case. What was super helpful was that it showed me all the requirements side by side with my specific situation so I could see exactly which tests I passed and which I didn't. It even suggested some alternatives that might work better for my tax situation.

Just wanted to follow up about my experience with that taxr.ai site. I was really skeptical at first but decided to try it since my situation with claiming my partner's parent was complicated. It actually walked me through all the requirements for both dependency and head of household status separately. Turns out I could claim her as a dependent because she lived with me all year, had no income, and I provided over half her support. But like others mentioned, that alone didn't qualify me for head of household. The system explained exactly why - for non-relatives to qualify you for HOH, they need to fit specific relationship requirements. The most helpful part was it showed me some adjustments I could make to my withholding to make up for not getting the filing status I wanted. Definitely saved me from making a mistake on my return!

If you're struggling to get answers from the IRS about your head of household situation, I feel your pain. I spent WEEKS trying to call them to confirm my eligibility with a similar dependent situation. Busy signals, disconnections, hours on hold...it was a nightmare. Finally tried https://claimyr.com and it was a game-changer. They have this system that somehow gets you through the IRS phone tree and holds your place in line. You can see a demo at https://youtu.be/_kiP6q8DX5c. They called me when an actual IRS agent was on the line! The agent confirmed my specific situation and gave me definitive guidance on my filing status and dependent questions. Honestly, being able to talk directly with an IRS rep and get an official answer gave me peace of mind that no online research could provide.

I have to eat my words about that Claimyr service. After posting my skeptical comment, I was so frustrated with my own situation that I decided to try it anyway. I've been trying to reach the IRS for almost a month about a similar head of household question (supporting my partner's disabled brother). Called 27 times with no luck. Used the service yesterday afternoon, and this morning my phone rang - with an actual IRS representative on the line! The agent confirmed that even though I support my partner's brother completely, I can't claim HOH status with him as my qualifying person since we don't have the required relationship. HOWEVER, she gave me some alternative deductions I could take that I had no idea about. The time and stress saved was absolutely worth it, and I got an official answer directly from the IRS.

Just to add another data point - I was in a similar situation a couple years ago. I supported my girlfriend's teenage sister who lived with us. I could claim her as a dependent under the qualifying relative rules since she lived with me all year and I provided more than half her support. But for Head of Household, the rules are stricter. You need a "qualifying child" OR a qualifying relative who is your parent, sibling, or certain other relatives. A girlfriend's mother unfortunately doesn't meet those relationship tests for HOH purposes. What I ended up doing was looking at other ways to reduce my AGI instead - maxing out 401k, HSA contributions, etc. Got me under the threshold I needed for a different credit.

One thing I haven't seen mentioned yet - be careful about the "member of household" rule if you're not legally married to your girlfriend. The IRS publication 501 states that your relationship must not "violate local law" to claim someone as a qualifying relative. In some states, cohabitation laws could technically come into play. California repealed their anti-cohabitation laws, so you should be fine, but it's something to be aware of when claiming non-relatives as dependents.