If the loss occurred in 2019, it has to be claimed on your 2019 return.

A loss is only claimed when it is "realized" or made real.  This may be tricky to figure out.  For example, if the stock is worth 1 cent per share, that's not "realized" until someone buys it from you at 1 cent per share.  Often, a broker will do that for you so you can realize your loss.

However, it should show as a sale on a form 1099-B.  Fidelity handles a lot of 401(k) and IRA accounts -- did this loss occur in a qualified retirement account?  If so, you can never declare the loss.  The whole point of a qualified retirement account is that whatever happens inside the account in between making a contribution and making a withdrawal has no tax consequences.  Your "loss" is the fact that you have less money to withdraw when you retire and so you pay less tax on those withdrawals.

If this was a regular account, you may need to call your broker to determine whether the loss has been realized yet and why it wasn't reported. 

Thanks Champ for your response. 
The loss occurred on regular Trading account on Fidelity Platform. I did call fidelity last year for this as it did not show up on my 1099 form they said, you can just declare it with the statement showing it is loss. No one really answered it on their side.

One person on call from fidelity said, you can declare it anytime in next few years as I presumed since all this was happening in Feb 2020, (presumably that is when broker bought that loss from me as Champ explained), so now this loss will show up on my 2020 taxable 1099 form, hence i did not declare it on 2019 returns hoping will be easier to do in 2020 return, but again loss does not show up on 2020 1099 form ...

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@Filing564 wrote:

Thanks Champ for your response. 
The loss occurred on regular Trading account on Fidelity Platform. I did call fidelity last year for this as it did not show up on my 1099 form they said, you can just declare it with the statement showing it is loss. No one really answered it on their side.

One person on call from fidelity said, you can declare it anytime in next few years as I presumed since all this was happening in Feb 2020, (presumably that is when broker bought that loss from me as Champ explained), so now this loss will show up on my 2020 taxable 1099 form, hence i did not declare it on 2019 returns hoping will be easier to do in 2020 return, but again loss does not show up on 2020 1099 form ...

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I guess I still have to know when the loss was actually realized.  If you have a stock on your statement showing a purchase price of $100 and a current value of 5 cents, that certainly a loss but it hasn't been realized until you sell the shares.  If the shares were declared worthless in 2019 and taken out of your account by the broker, then your loss was realized in 2019 and you have to amend your 2019 return to claim it. 

Thanks Champ, for being so helpful. Appreciate it.

final resolution, based on your answer I rechecked my 1099 form. Fidelity did include the losses in 2020 1099 form as you mentioned they realized this loss in Feb 2020 and hence added it in my year end tax statement as loss. This is solved.

I invested $84,000 in a company called GWG. They convert insurance policies into cash for the policy holders.  It’s currently in bankruptcy 11 meaning that the debtors and creditors are trying to work through the bankruptcy court and try to pay the investors. But recently the assets of the company are slowly dwindling to the point the not much will be left to pay the investors. Can I claim the total amount as a loss or do I have to wait out until the court decides what to do? And if I can report the total loss where do I report it on my turbo tax (delux) software. Respond to [email address removed]  vietvet 007. 

@veteran007 

You have to wait until the loss is realized--that is, made real by some final act that either pays you a small amount or declares the stock to be legally worthless.  As of now, it is still only a potential loss.  If you don't want to wait for the bankruptcy to conclude, maybe you could sell your stock to your broker for $1, that would make your loss real, and the broker would take any upside (if the settlement was more than $1, they would keep it).  Some brokers will do this for you, but not all.

When the loss is realized, you report it as a capital loss in Turbotax. You can use it to offset other capital gains.  If you don't have any capital gains, you can deduct $3000 of the loss and carry the rest forward to the next year when you can again deduct up to your gains, or $3000 with a carry-forward, and so on.