(MONEY Magazine) – If you expect ultimately to save money under tax reform, don't start making plans to spend it just yet. The reason: 33 states plus the District of Columbia link their tax systems to the federal tax code in such a way that their revenues could automatically increase under reform. Unless the legislatures in those states reduce the tax bite, you could wind up losing to your state some -- and in a few places, all -- of your federal tax savings. Colorado is a typical example. A family filing jointly should save $720 in federal taxes in 1991, the year tax reform will be fully phased in, but they could pay $54 extra in state taxes that year. According to the Advisory Commission on Intergovernmental Relations, a research group in Washington, D.C., the big losers could be taxpayers in the following states (with the scheduled rise in state taxes by 1991 in parentheses): Colorado (22%), Hawaii (15%), Iowa (18%), Kansas (18%), Louisiana (28%), Minnesota (15%), Missouri (18%), Montana (19%), Oklahoma (18%), Oregon (19%) and Utah (19%). Smaller increases occur in another 22 states and Washington, D.C.* The 33 states and the District of Columbia in which local income taxes may go up apply their own rates to the adjusted gross income, the taxable income or other figures that you report on your federal return. Under reform, many taxpayers will see their taxable incomes on their federal returns rise because of the loss of such breaks as the 60% capital-gains exclusion and deductions for consumer interest and state sales taxes. Thus, unless state tax laws are rewritten, some top-bracket residents in many states could face outrageous tax hikes. For instance, a two-earner couple living in Oregon with a combined income of $60,000 is in line for a 43% state tax increase this year. Will the Oregonians really have to cough up the extra cash? ''It's virtually impossible,'' says Richard Peterson, an economist with the state's Legislative Revenue Office. ''Can you imagine the legislature permitting such an increase?'' ''In reality,'' says Karen Benker, economic analyst for the National Association of State Budget Officers, ''the states will be under considerable pressure to do everything they can to keep tax revenues at their current levels.'' This may be true even in states whose residents may be hoping for a local windfall because of tax reform. For instance, in Nebraska, North Dakota, Rhode Island and Vermont, the state income tax is simply a percentage of a resident's federal tax bill. The last three have taken action to raise rates in the face of a revenue loss. Nebraska is expected to do likewise. Four other states -- Arkansas, New Jersey, North Carolina and Pennsylvania -- will have a negligible decrease in state income tax revenues. Many states will base their actions on the outlook for their local economies. Lloyd Looram, state tax expert at the accounting firm of Arthur Andersen in New York City, explains, ''As a rule of thumb, states with treasuries that aren't hurting for cash will not accept the windfall.'' Ohio has already made an across-the-board rate reduction of 7% for 1987 and 8% for 1988 to maintain taxes at their current level. In New York, where Governor Mario Cuomo has promised that ''any revenue gains will be returned to the people,'' the legislature is expected to change the state's tax code by late spring so that taxpayers will be spared a projected $2 billion tax increase.

But, cautions Karen Benker, ''It will be very hard for states like Louisiana and Oklahoma, which have suffered from the collapse of the oil industry, to give back the extra revenue.'' Experts on local taxes expect most of the windfall states to take some action this year. Says Philip Krevitsky of the Arthur Young accounting firm in New York City: ''They really can't postpone action and leave people unable to do any tax planning.'' He notes, however, that some states with budget problems might be tempted to delay making the changes and thus absorb a year's worth of the extra revenue. Some legislators in Colorado and Illinois, for example, are eager to do this. (For a rundown on what the top revenue-gaining states are expected to do, see the table at right.) Who stands to gain or lose in the great state tax reshuffle of 1987? Most states are looking at changes that will benefit the largest number of voters -- usually a matter of just lowering rates. But some states, such as Maine and New York, are considering removing low-income taxpayers from the tax rolls, and Illinois may add deductions for the elderly and the blind. Such redistributions of the tax burden could mean a heavier load for upper- and middle-income taxpayers in many states. Says Arthur Young's Krevitsky, ''It will be fun to see how the states handle this one.'' FOOTNOTE: *Alabama (1%), California (9%), Connecticut (11%), Delaware (10%), District of Columbia (10%), Georgia (10%), Illinois (7%), Indiana (4%), Kentucky (14%), Maine (12%), Maryland (8%), Massachusetts (1%), Michigan (6%), Mississippi (4%), New York (9%), Ohio (7%), Virginia (9%), West Virginia (11%), Wisconsin (4%). Arizona, Idaho, New Mexico and South Carolina could also have increases of less than 15%, but the exact amount is not known.

BOX: Which states may return the windfall to you -- and which ones won't These 23 states and Washington, D.C. stand to get the biggest bonuses from tax reform -- shown below as percentage hikes in their personal income tax revenues -- unless they return the money to taxpayers. The increases were ) estimated by the Advisory Commission on Intergovernmental Relations. Our early-January forecast of what the states and Washington, D.C. might do came from local officials and political experts.

Calif. 9%: May reduce rates to return the revenue to taxpayers

Colo. 22%: Wants to keep some of the money to fund education and rebuild roads

Conn. 11%: May cut capital-gains taxes to return the windfall

Del. 10%: Some legislators want to keep the gain but may have to return it in 1988

Ga. 10%: State is flush and will give back all of the additional revenue

Hawaii 15%: May lower tax rates to return the windfall in 1987

Ill. 7%: Officials want to keep the money but may have to give some back in 1988

Iowa 18%: Can afford to return only part because of oil's and agriculture's collapse

Kans. 18%: Despite the farm depression, the state aims to forgo the extra revenue

Ky. 14%: Needs the money to stave off a state budget deficit

La. 28%: Will keep all the money to offset lagging revenues from oil

Maine 12%: May reduce tax rates to give back some of the windfall

Md. 8%: Possible 5% tax credit on all 1987 returns; permanent cuts will come later

Minn. 15%: Will pay back the money by phasing in lower rates and fewer brackets

Mo. 18%: May keep the windfall for 1987 but give some back in 1988

Mont. 19%: A giveback is unlikely because of the downturn in agriculture and oil

N.Y. 9%: May cut taxes as early as April to offset the windfall

Ohio 7%: Individual tax rates have been reduced by 7% for 1987 and 8% for 1988

Okla. 18%: The local oil economy is too damaged to permit a giveback anytime soon

Ore. 19%: Financially strong and plans to return the extra revenue

Utah 19%: Will keep the windfall and boost other taxes because of a budget crunch

Va. 9%: May keep the windfall in 1987 but will return it in 1988

Wash., D.C. 10%: Wants to keep the money but may have to give back most of it

W.Va. 11%: Must keep some of the windfall to eliminate a $40 million deficit