Medicare wages are the earnings that are subject to Medicare tax. These wages include all compensation for employment, such as salaries, bonuses, commissions, and tips. The Medicare tax is part of the Federal Insurance Contributions Act (FICA) tax, which funds the Medicare program providing health insurance to individuals aged 65 and older, and to certain younger people with disabilities. According to the Internal Revenue Service (IRS), all wages, salaries, and tips are generally subject to Medicare tax unless specifically exempted (source: IRS).