I think there is like a five year window. If you have transferred everything into someone else's name over five years ago, then the goverment cannot come after it if you get sick. Any time before the five years and the gubment takes your assets to pay the bills.
Unless there's been a change that I'm not aware of, I believe you're thinking about the rules for Medicaid eligibility. In order to be eligible for Medicaid, you are not allowed to transfer significant assets for five years prior to your Medicaid application. Otherwise, they will act as if you still own the asset and require that you continue to "spend down" an amount equal to the FMV of that asset before becoming eligible. Similarly, if you are accepted for Medicaid and it is later determined that you transferred assets within that five year window, then they could seize those assets if there are any unpaid medical bills, or if the government demands repayment for the medical bills it covered while you were inappropriately receiving Medicaid.
If you're terminally ill or otherwise racking up medical bills and you suddenly start transferring assets, and shortly thereafter you die, then maybe creditors could take the estate to court and assert that those transfers were a fraudulent attempt to avoid paying bills, but I don't think there's a federal law out there that specifically gives the government a five year window to look back and automatically seize assets that were transferred.