How do I calculate "cost basis" for inherited Praxair stock that was merged with Linde PLC? It was not on the 1099-B. Would this be the value of the Praxair stock?

[hamp]

How do I calculate "cost basis" for inherited Praxair stock that was merged with Linde PLC in November 2018? I received the same number of shares (180) as the original stock, but the value was slightly higher than the value of the Praxair stock. I received  a 1099-B for the transaction, which stated the "Proceeds", but didn't give a value for "Cost  or other basis". Turbotax interpreted this as profit, which added to my income, but I never saw anything except the new stock certificate. So now my taxes are very high. Should the "Cost Basis" be the value of the Praxair stock at the time of the merger, and would this likely reduce my taxes?

[hbl3973]

For inherited assets, the cost basis is the fair market value of the stock on the date of death. (If the estate chose the 6 month later valuation date, then the FMV on that date.)  If that date fell on a weekday, you can use the average of the high and low stock price for that date.  If it fell on a weekend or holiday, take the averages for the business day prior and the business day after and average those two.  You can use https://www.praxair.com/investor-relations/stock-information-and-price to look up historical Praxair prices.