Self-employed individuals can deduct premiums for their health coverage as an above-the-line deduction under certain conditions; no itemizing is required. While the IRS has never specifically said the COBRA premiums count as self-employed health insurance, it appears to be deductible as an above-the-line deduction for a self-employed individual paying these premiums.
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.