The 1095B and 1095C indicates your employer provides your health insurance coverage. If you received a letter then you may not have checked the box indicating you've had health insurance in 2019. You just need to send an amended tax return with this box checked. The 1095 forms are for your record and does not need to be sent to the IRS. There is no individual mandate penalty for 2019. This is just an administrative issue.
The Health Coverage Tax Credit is not available to most taxpayers. As the IRS says,
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Eligibility for the HCTC is restricted to the following groups of individuals:
" See this IRS webpage. That is, this credit is generally available to taxpayers who have lost their jobs due to foreign competition.
Every year, we see taxpayers who accidentally apply for this credit, not realizing that they are not eligible for it.
If you were actually eligible for it, you should have receive a letter form the IRS stating that you were. This is the proof that the IRS is looking for. Do not send the IRS the 1095-C and 1095-B.
In terms of the IRS letter, if you realize that you are not eligible for this credit (see the IRS link above), write back to the IRS explaining that you took this credit by mistake and asking them to change your return. If they agree to do this, they will recompute your taxes and send you a bill for the difference. In this case, you don't need to amend your return and send it to them, because they have already done it (unless they tell you differently).
If you have a TurboTax return on which you applied this credit and want to remove it, please delete form 8885.
Online:
Click on Tax Tools on the left, then Tools underneath, then Delete a Form in the center - scroll down and delete form 8885.
CD/download software:
Click on Forms at the upper right, scroll down the forms list that appears on the left, then click on 8885, then at the bottom of the View Pane, click on Delete Form.