The big kahuna of tax is the federal return, but that doesn't mean you can ignore the state return.
Though much of the income and deduction information that goes on the state tax return flows from the federal one, which is usually prepared first, special situations and breaks give the Massachusetts form its own character and complications.
Among the twists for 2006, for example, Bay Staters may be able to: claim a 2006 deduction for certain commuting expenses in excess of $150, take deductions and credits for home heating bills and energy conservation not fully claimed for 2005, and claim an increased personal exemption.
And unlike the federal government, Massachusetts does not tax Social Security benefits and allows a limited state deduction for Social Security contributions withheld from paychecks.
Accountant Norman Posner in Chestnut Hill cautions, however, that taxpayers may find themselves barred from some specific state breaks when their income exceeds certain limits. And some federal deductions, such as for college tuition or contributions to an IRA, are not allowed when figuring state tax.
The biggest departure between the Internal Revenue Service and the Massachusetts Department of Revenue involves returns filed by same-sex married couples -- recognized as legitimate wedlock by the state but not by Uncle Sam.
One result is extra work.
"I had a situation where a federal and state return that would normally take about three hours doubled in time," says accountant Lillian Gonzalez, of Sandberg, Gonzalez & Creeden in Stoughton. Even on less-complex returns she says to typically figure on at least an hour of extra work.
The big task is preparing and reconciling two separate federal returns for the partners as singles and then a joint state return as a married couple. This often involves having to do some theoretical figuring as if they were filing a joint federal return in order to arrive at entries for their joint state return.
"We still have the same level of aggravation with this, but we've become better at handling it," says Gonzalez, now in her third season of preparing same-sex returns.
For more information, the Massachusetts Department of Revenue has a comprehensive website, mass.gov/dor, where you can find forms, publications, and other services -- including checking on a refund or making a payment. Or you can call toll-free 800-392-6089 , or if you're out of state, call 617-887-6367.