Q: My long term girlfriend recently passed without a will.

A: You are not an heir at law, so the siblings cannot simply disclaim their interests because disclaimers are treated as if they had predeceased your girlfriend, and that would not result in the estate assets going to you. However, if you had a legal claim against the estate based on contributions toward the purchase, upkeep, maintenance, etc., of the house and/or pursuant to any other agreement with your girlfriend by which she owed you any money, then the siblings (the legal heirs of the estate) could sign a settlement agreement with you as a claimant to the estate to transfer the house to you in full discharge of your claims. Alternatively they could gift their interests in the house to you, but then they would each file a gift tax return to report the value of their gifts to the extent they exceed the federal $15,000 annual gift tax exclusion. When gift tax returns are filed, the giver of the gift can elect to pay no gift tax, and the excess amount of the gift is deducted from their Unified Credit against the estate and gift tax that applies to their own estate when they die (the federal credit is currently $11,700,000 for people who die in 2021, and the Maryland estate tax credit is $5,000,000, so the siblings' estates would need to exceed those amounts before estate taxes would be due). There should be no Maryland inheritance tax imposed, since you would not be an heir receiving a distribution under the estate; rather, you would be either a creditor settling a claim or a donee of a gift the heirs make to you of their inheritance. I believe under both scenarios, you would receive a tax basis in the property equal to the fair market value of the house at the time of your girlfriend's death.