Massachusetts Form 11B is an income tax return form used by Massachusetts residents who are filing as individuals. The form is used for calculating the tax due on the taxpayer's income, deductions, and credits. There are two types of Massachusetts Form 11B: the Long Form and the Short Form. The Long Form is used for taxpayers who have itemized deductions or certain credits, while the Short Form is used for taxpayers who are taking the standard deduction and are not claiming any credits. Both forms are available on the Massachusetts Department of Revenue's website.