A line was dropped from an answer in the Your Balance Sheet column in yesterday's Washington Business, making the answer incorrect. The paragraph should have read: Keep in mind we're only talking about earned income -- wages, commissions, fees, earnings from self employment. There is no ceiling on income from investments (interest, dividends, capital gains), from pension and retirement payments or from deferred-compensation plans such as 401 (k).

Come Jan. 1, Uncle Sam will have his usual bundle of goodies for all recipients of Social Security benefits. Beginning with the checks due to be received Jan. 3, monthly benefits will go up 3.5 percent.

The ceiling on earnings also will go up at the new year. Beneficiaries aged 65 through 69 will be permitted to earn up to $7,320 in 1985 without any loss of Social Security benefits. This compares with the 1984 ceiling of $6,960.

For those under 65, the limit jumps from $5,160 to $5,400. People who are 70 or older may earn an unlimited amount without any reduction of benefits.

If you're under age 70 and exceed whichever of the two limits applies, one dollar of Social Security benefits will be withheld for every two dollars that your earnings exceed the ceiling. (If you can hang on until 1990, the reduction in benefits goes to one dollar for every three dollars over the maximum.)

Keep in mind that we're talking only about earned income -- wages, commissions, fees earnings from self-employment, dividends, capital gains from pension and retirement payments or from deferred compensation plans such as 401 (k).

What Uncle Sam giveth, he also taketh away -- so on Jan. 1 Social Security taxes will go up, too. The tax rate for workers will increase from 6.7 percent to 7.05 percent; and the wage ceiling on which the tax is taken goes up to $39,600 from this year's $37,800.

Self-employed folks get a similar increase, from 11.3 percent to 11.8 percent, and figured on the new higher ceiling. (The nominal rate is somewhat higher, but a credit -- which is gradually being phased out brings the true rate to the amount shown.)

The new year also brings the introduction of a new element in the federal tax structure -- automatic indexing. All the fixed-dollar values in the tax regulations are increased each year based on the increase in the official cost of living index for the preceding 12-month period ending Sept. 30.

The figure for 1985 is 4.08 percent. Accordingly, the value of each presonal exemption and exemption for dependents will rise from the present $1,000 to 1,040. Zero-bracket amounts (the old standard deduction) will increase from $3,400 to $3,540 on a joint return, and from $2,300 to $2,390 for a single taxpayer.

All tax brackets will move up as well; the new bracket amounts will be used to calculate the values in the tax tables, and will appear in the tax schedules for those who compute their own taxes.

Don't use these new numbers on your 1984 tax return -- the one you will be working on this winter. They will apply to your 1985 tax return -- the one due April 15, 1986.

Q: My question has to do with income averaging. In 1983, due to the sale of some property, my taxable income was almost $26,000 greater than in 1982 ($83,331 vs. $57,334). Income for the preceding years was similar to 1982 income. When I completed Schedule G, I found that my tax after averaging was exactly the same as without averaging. Is this possible? My 1983 Schedule G, which I did not send to the IRS, is enclosed.

A: Your Schedule G was completed correctly, and yes -- it is possible to come out with the same tax either way. You will usually end up with a lower tax with Schedule G because spreading your excess income as if it had been received over four years will in most cases drop you into a lower tax bracket.

In your case the arithetic works out differently. Both the large "surplus" in the normal tax calculation and the small "surplus" you get by averaging fall into the 44 percent tax bracket. As a result, after all the dividing and multiplying are done, your tax works out exactly the same either way.

Incidentally, for 1984, averaging on Schedule G will be tougher. Income for only the preceding three years will be averaged, instead of four; and the current year's income will have to exceed 140 percent of that average instead of 120 percent, as in past years.