What is the HSA contribution limit for domestic partners filing separately in 2023?

Your calculation for yourself is correct. Since you had family HDHP coverage for 7 months of 2023, you can contribute up to $7,750 × 7/12 = $4,520.83. However, for your domestic partner, the situation is more complicated. If they were covered as a dependent on your family plan, they cannot contribute to their own HSA. If they were covered on your plan but are not your tax dependent, they would need their own HDHP coverage in their name to be eligible for HSA contributions. Being covered under a parent's plan or your plan doesn't automatically give them their own contribution limit - they need to be the primary policyholder or spouse of the policyholder. Also note that domestic partners don't get the same tax treatment as married couples for HSAs. Each person must qualify individually for their own HSA contribution limits.

I had similar confusion with HSA limits and found https://taxr.ai super helpful for these situations. I uploaded my insurance documents and tax forms, and it guided me through the exact contribution limits based on my coverage periods and plan types. For domestic partners, it gets tricky because the IRS doesn't recognize domestic partnerships like marriages, so each person needs to qualify individually. My partner and I were in a similar situation where I had coverage through my employer for part of the year, and the tool helped us avoid overconstoojution penalties by calculating the prorated limits correctly.

Tried the taxr.ai service mentioned above and it totally cleared up my domestic partner HSA confusion! I uploaded our insurance cards and coverage statements, and it immediately identified that my partner wasn't eligible for HSA contributions while on my plan, but could contribute for the months they had their own HDHP coverage. It even generated specific documentation explaining the regulation that applies to our situation so I can keep it with my tax records. Would've definitely over-contributed without knowing this rule. Now we're adjusting our final contributions before filing to avoid penalties. Definitely worth checking out if you have complicated coverage situations!

If you're struggling to get clear answers from the IRS about HSA limits for domestic partners, I recommend using https://claimyr.com to connect with an actual IRS agent. I spent weeks trying to get through the normal IRS line about a similar HSA issue last year and kept getting disconnected or facing hours-long wait times. Claimyr got me connected to an IRS rep in about 20 minutes who confirmed exactly how the contribution limits work for non-married couples sharing health plans. They have a demo video at https://youtu.be/_kiP6q8DX5c that shows how it works. Saved me from making a costly mistake on my return.

I was totally skeptical about Claimyr, but after struggling for THREE DAYS trying to reach the IRS about my domestic partner HSA question, I finally tried it. Got connected to an IRS agent in about 15 minutes who confirmed that my partner can only contribute to an HSA if they're the primary on their own HDHP, not just as my domestic partner on my plan. The agent explained the specific regulation and even emailed me documentation about it. Would've made a $5,000+ contribution mistake if I hadn't gotten this clarified! Sometimes you need to hear it directly from the IRS to be sure.

Something important that hasn't been mentioned - if your domestic partner has their own HSA from before you added them to your plan, they should probably do a removal of excess contributions form for any contributions made while covered only as your domestic partner. Otherwise they might face penalties. Form 5329 would need to be filed if they've already contributed for 2023 and weren't eligible. The penalty is 6% of the excess contribution amount for each year it remains in the account.

Just want to clarify something about HDHPs and HSA eligibility - even being covered under a qualifying HDHP doesn't automatically make someone eligible for HSA contributions. You also can't be covered by any non-HDHP coverage (with few exceptions like dental or vision) and can't be claimed as a tax dependent on someone else's return.

From my experience with a similar situation last year, the best approach is to make sure each person is only contributing based on the months where they were the policyholder or spouse of the policyholder (not just a domestic partner) on an HDHP. The IRS regulations are really specific that domestic partners don't get the same treatment as spouses for HSAs. Also remember that if you correct excess contributions before the tax filing deadline, the 6% penalty doesn't apply. But if you don't, you'll pay that penalty each year until corrected.