I inherited a house, the "cost bases" was bigger than the sale price (inherited and sold same year) -- will that reduce my tax as per the 1099-S ?

[HelenaC]

No, because losses from personal property cannot be claimed as a deduction on your taxes. It's an unallowed loss.

When you inherit property after the owner dies you automatically receive a "stepped-up basis." This means that the home's cost for tax purposes is not what the now-deceased prior owner paid for it. Instead, its basis is its fair market value at the date of the prior owner's death.

See Where do I enter the sale of a second home, an inherited home, or land?