How many years past may I claim unreimbursed tax deductions?

[randyhough1]

I have unreimbursed deductions from past years and would like to claim them this year. How far back may I use these deductions?

[xmasbaby0]

You can amend a tax return for up to three years to receive an additional refund; after three years it is too late.

Not sure what you mean by "unreimbursed tax deductions"---itemized deductions do not affect your refund unless you have enough itemized deductions to exceed your standard deduction.  What tax year are you wanting to amend---and what deductions do you want to add?

[xmasbaby0]

"...would like to claim them this year. "

You do not mean you think you can put itemized deductions from some past years on your 2023 tax return, do you?   You cannot do that.   Deductions must be entered for the specific tax year.   You might be able to amend a 2020, 2021 or 2022 return in order to use a deduction if you forgot to enter it for the tax year in which you filed.  You cannot put past year itemized deductions on your next tax return.

[Opus 17]

If I understand your question, never.  Tax deductions can only be taken in the year the expense is paid.  You can't take the standard deduction for several years and "stack" all your itemized deductions into one year to get a larger tax benefit.

The rules for business assets and startup expenses are diferent, but we need more details to know what you are talking about. 

[SteamTrain]

Well....there's almost always exceptions...even though rare....SO you'd really have to tell us exactly what you are talking about.

There's Only one exception that I can think of for the moment:

Normal income deductions can't be carried over to subsequent years, but for folks who make absolutely HUGE charity donations, some of the excess $$ (those not allowed to be used in one year) can sometimes be used in a subsequent year.  But HUGE means charity donation $$ exceeding 60% or perhaps even 100% of AGI for a particular year  (Not sure if 100% was in effect for some or all of particular years in 2019-thru-2022).

[SteamTrain]

But your use of the word "Unreimbursed" seems to point to medical expenses.

,,,,as already noted..thsoe you'd have to amend the particular year involved...and even then, you'd have to be using itemized deductions for that year's forms for it to be any advantage for you........and those unreimbursed med expenses would have to exceed 7.5% of your AGI for that year..

[Opus 17]

Even in the case of the charity carry-forward, the taxpayer must report and claim the full donation value on their tax return.  Then, if there is a limitation, they can carry it forward to the next year.  There is no rule where you can simply leave the deduction off your return entirely and then claim it in a later year.