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.
Rules that limit the deduction of losses from passive activities to income from other passive activities. Passive activities include investment rental operations or businesses in which you do not materially participate.