Main Home – Usually, the home you live in most of the time is your main home; your home can be a house, houseboat, mobile home, cooperative apartment, or condominium.

Married Filing Jointly – The filing status you can choose if you are married and both you and your spouse agree to file a joint return. On a joint return, you report your combined income and deduct your combined allowable expenses. You can file a joint return even if one of you had no income or deductions.

Married Filing Separately – The filing status you can choose if you are married and do not want to file jointly with your spouse. This method may benefit you if you want to be responsible only for your own tax or if this method results in less tax than a joint return. If you and your spouse do not agree to file a joint return, you may have to use this filing status.

Material Participation – Generally, any work you do in connection with an activity in which you own an interest is treated as participation in the activity. Material participation is strictly defined in the Internal Revenue Code and is one of several tests used to determine that a trade or business is not a passive activity.

Medicare Tax – Tax paid for Medicare. This amount is 1.45% of wages for employees and 2.9% of net profit for self-employed taxpayers.

Medicare – A federal program that pays for certain health care expenses for people age 65 or older.

Modified Accelerated Cost Recovery System (MACRS) – MACRS provides a uniform method for all taxpayers to use to calculate the depreciation for each asset. Using the basis, class life, and the MACRS tables, you can calculate the deduction for each asset in the year it is placed in service and each subsequent year of its class life.

Modified Adjusted Gross Income – Adjusted gross income is sometimes modified for specific purposes (such as for the education credits, the Adoption Credit, the Child Tax Credit, and determining taxable Social Security benefits). For each purpose, the modification may be different, so you need to read the instructions carefully.

Multiple Support Agreement – When trying to determine who can take an exemption for a dependent, sometimes no one person provides more than half of the dependent’s support. Instead, two or more persons, each of whom would be able to take the exemption but for the Support Test, together provide more than half of the person’s support. When this happens, you can agree that any one of you who individually provides more than 10% of the person’s support, but only one, can claim an exemption for that person. Each of the others must sign a statement agreeing not to claim the exemption for that year. A multiple support declaration identifying each of the others who agreed not to claim the exemption must be attached to the return of the person claiming the exemption.