Yes. The IRS has indicated (https://www.irs.gov/pub/irs-wd/1228037.pdf) that all Medicare premiums are similar to other health insurance, and that this deduction rule extends to Medicare premiums for coverage of a self-employed individual’s spouse, dependent, or child under age 27.
Advance payment of current tax liability based either on wage withholdings or installment payments of your estimated tax liability. To avoid penalties, you generally must pay to the IRS either 90% of your final tax liability, or either 100% or 110% of the prior year’s tax liability, depending on your adjusted gross income.