After you file

The deduction for PMI expired at the end of 2017 and as of this date Congress has not renewed the deduction for tax year 2018.

See IRS Schedule A Itemized Deductions instructions on the first page - https://www.irs.gov/pub/irs-pdf/i1040sca.pdf

Expired deduction for mortgage insurance premiums . At the time these instructions went to print, the deduction for mortgage insurance premiums had expired. You can't claim a deduction for amounts paid or accrued after 2017.