an issue. when the LLC was formed, the IRS says it can't use the qualified joint venture election to escape filing a partnership return. A domestic LLC with at least two members that does not file Form 8832 is classified as a partnership for federal income tax purposes. so from the year the LLC was formed thru the date in 2017 when your father died a partnership return should have been filed. at the date of his death the partnership terminated (a partnership can not have a single member) so for the rest of 2017 assuming your mother inherited your father's interest, the reporting should have been done on her schedule E. you mother's tax basis in her share would remain the same. she would get a stepped-up basis in her husband's share. the basis for depreciation on her share would not change. since the stepped up basis for her husband's share in the house would get stepped up it should have been depreciated on the stepped-up basis.
the IRS says depreciation allowed or allowable so if the depreciation wasn't taken on the steeped up basis the IRS says it was for purposes of computing gain. loss, depreciation recapture upon disposition
so it may be necessary for your mother to amend her 17 and 18 returns to take the correct depreciation
(any depreciation taken on her husband's share while he was alive disappears) .
