A "lapse" is caused by TurboTax misunderstanding your input. If one spouse does not have an HSA, then they never go through their part of the HSA interview wherein they tell TurboTax what type of HDHP coverage they had. Hence, TurboTax thinks they don't have any HDHP coverage for the current year (2024).
But when you answer "Family" or "Self" to the question about HDHP coverage for that spouse for December 1, 2023, you have just told TurboTax that that spouse had coverage in 2023.
This is why TurboTax thinks there has been a lapse, when there actually hasn't been one. And this is why it is OK to tell TurboTax "NONE" for that spouse on the question about 2023. It is to put an end to TurboTax's confusion.
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