I am 70 and 1/2 as of February 13, 2019. Can I still make an IRA contribution for the tax year ended 12/31/18 as long as I do so before I file my 20181040?

[fanfare · Accepted solution]

Contributions must be made by due date. Contributions can be made to your traditional IRA for a year at any time during the year or by the due date for filing your return for that year, not including extensions.

this is so, even if you e-File today.

make sure the custodian knows to mark it "For 2018".

[dmertz]

As long as you have sufficient compensation to support an IRA contribution, you can make a traditional IRA contribution for 2018 because you did not reach age 70½ until 2019.