Scattered throughout the accompanying text you will find a number of changes that affect the preparation of your 1984 tax return. Last year's tax legislation also made changes -- some for 1984, others for 1985 and later years -- that do not have a direct impact on the 1984 return itself but may have an effect on your tax planning and strategy for 1985.

Here, in summary form, is a review of the major changes.

Tax rates. Rates for 1984 are slightly lower than the 1983 rates because the third installment of the tax reduction measures passed in 1981 took effect on July 1, 1983. While there was no further reduction in 1984, the lower rates that applied to just six months of 1983 were in effect for the entire year of 1984.

Indexing. 1985 is the first year of tax indexing -- modifying rates to compensate for inflation. Tax brackets, the personal exemption, exemptions for dependents and the zero-bracket amount all increase by 4.08 percent, reflecting the rise in the cost of living for the past 12 months. (As a practical matter, each figure may not be changed by precisely that percentage because of rounding.)

Capital gains. The holding period for a sale of property to qualify for long-term gain or loss was reduced from one year to six months, for assets acquired after June 22, 1984.

Interest exclusion. The exclusion of specified amounts of interest from taxable income, which was scheduled to go into effect on Jan. 1, 1985, was repealed.

Income averaging. Beginning with the 1984 tax return, it has been made more difficult to qualify for this technique for reducing the tax bite in a year of higher-than-normal income.

Fringe benefits. The taxing of fringe benefits, long a source of contention between Congress and the IRS, has been at least partially resolved. The 1984 law spells out the rules, insuring the continuing tax-free nature of some benefits but tightening the rules on others.

Real estate. For investment real estate placed in service after March 15, 1984, depreciation must be based on a period of 18 years rather than 15 years (exception: low-income housing).

Business expense. New rules were instituted in 1984 restricting the investment tax credit and rapid depreciation for cars, computers and other specific business property to assets used primarily for business purposes. Beginning in 1985, detailed contemporaneous logs must be kept of the use of "split use" assets -- those used both for business and personal applications -- and for travel, entertainment and gift expenditures claimed.

Diesel car owners. For 1984, there is a one-time tax credit for original purchasers of 1979 or newer diesel cars, vans or light trucks, to help compensate for an increase in the federal tax on diesel fuel.

Foreign income. The amount of exclusion of foreign earned income had been scheduled to rise to $85,000 for 1984, and to $90,000 this year. Instead, the exclusion ceiling will stay at $80,000 through 1987, and is now scheduled to be increased beginning in 1988.

Annuities. Some restrictions have been placed on distributions from annuities prior to reaching age 59 1/2.

Gift/estate tax. The top rate for the combined gift/estate tax has been frozen at 55 percent through 1987, dropping to 50 percent for 1988 and later years.

Head of household. Beginning in 1985, a divorced parent may claim head-of-household status if he or she provided the principal home for a child for more than half the year (instead of the full year, as had been required). In addition, the child need not be a dependent, if that status is a result of a pre-1985 divorce agreement or of a waiver by the custodial parent.

Child of divorced parents. The new rules specify that, beginning in 1985, the custodial parent is entitled to the dependent exemption unless he or she specifically waives the right. Regardless of who gets the exemption, either parent -- or both -- may claim a Schedule A deduction for medical expenses paid on behalf of the child.

Alimony v. child support. There have been changes in the rules for determining whether payments resulting from a divorce represent alimony or child support -- an important determination because it affects tax liability. The new rules are complex and confusing -- you may need professional help in applying them to your specific circumstances.

Alimony for IRAs. Beginning in 1985, taxable alimony payments are considered "compensation" to the recipient for the purpose of qualifying for an IRA.

Divorce settlements. For transfers of property after July 18, 1984, incident to a divorce settlement, there will be no capital gain or loss imputed that would generate any tax liability. However, the spouse receiving the property will carry over the adjusted basis, rather than a stepped-up basis, with regard to a later sale.

IRAs. An extension for filing your income tax return no longer provides a similar extension for making qualifying IRA deposits for the preceding tax year; the deadline is now April 15 in any case.

Keogh. The rules for calculating the maximum amount that may be contributed to a Keogh plan have been modified. Although there is still some conflicting language to be resolved, for the present you may deposit up to 20 percent of your net income from self-employment.

Medical expense. On your 1984 tax return you may claim, as a Schedule A deduction, up to $50 a day for lodging expenses away from home for the purpose of obtaining qualifying medical care.

Contributions. Starting in 1985, you are required to obtain a professional appraisal to substantiate the value of any noncash contribution in excess of $5,000. An appraisal is not required for publicly traded securities; and for nonpublicly traded securities, the minimum value goes to $10,000.

If you use your own vehicle in performing donated services for a qualified organization, for 1985 you may use a standard mileage rate of 12 cents instead of the 9 cents a mile authorized through 1984.

For taxpayers who do not itemize, the deduction for charitable contributions is liberalized for this year and for 1986. For 1985, you will be permitted to claim 50 percent, and for 1986 100 percent, of all qualifying contributions, with no ceiling except for the standard limit of 50 percent of adjusted gross income. Under present law, this deduction for non-itemizers ends after 1986.

Social Security benefits. For 1984 and later years, a part of your Social Security benefits may be subject to federal income tax.

Earned income credit. Beginning in 1985, the rules for qualifying for the earned income credit are eased slightly. The rate of the credit goes from 10 to 11 percent and the earnings limit are increased throughout the range of the credit.

Tax shelters. Organizers of certain tax shelters considered by the IRS to be potentially abusive must register the shelter with the IRS if any iterest is first sold to an investor after August 31, 1984. The sponsor must provide the registration number to all investors, and each investor, in turn, must include that number on any tax return on which a deduction or credit from the shelter is claimed, using IRS Form 8271.

Investors. The 1984 tax law imposed several new rules affecting sophisticated investors. The subjects covered included broad-based market index options, tax straddles, tax-exempt equity leasing and original-issue discount and market discount bonds. If you are concerned with any of these, consult your broker and tax accountant, and review the explanations in IRS Publication 17.

Interest-free loans. New rules on below-market and no-interest loans impose possible income tax and gift tax liability in those cases where there is a potential for tax avoidance.

Appeals. The dollar limit for Tax Court small cases has been raised from $5,000 to $10,000.