I am distressed by the growing insistence of writers in The Post to pit the young against the old in our national budget debate. Robert J. Samuelson's article ''Pampering the Elderly'' {op-ed, Oct. 24} is a classic case in point. A vast majority of the older Americans have realized no net gain in their standard of living over the past 10 years. The children of our nation have suffered, not at the hands of their elders but at the hands of Reagan/Bush economic priorities and a 100 percent growth in defense spending.

Thirty-one percent of Americans over 65 live on less than $10,000 per year; an even greater number are near poor. Two-thirds of these citizens are women, most of whom live alone. Only 20 percent of women over 65 have any source of income other than an average $511 per month Social Security check.

Twenty-five years ago Medicare was enacted in part because older Americans were spending, on average, 20 percent of their incomes on health needs. Today, even with Medicare, older Americans still spend 20 percent of their incomes on out-of-pocket health care costs for coverage that usually falls far short of their needs. The Medicare program has absorbed more than $30 billion in cuts over the past nine years, and it seems that at least another $40 billion will be agreed upon for the next five years. A Social Security cost-of-living adjustment is not an increase in benefits, but insurance against a decrease. A one-time elimination of the COLA would immediately throw 130,000 Americans below the federal poverty line.

Long-term care costs remain a major economic threat to Americans of all ages. The average nursing home in the United States costs $25,000 per year. Within one year of entering a nursing home, 90 percent of all Americans will spend themselves into poverty. We remain the only Western nation other than South Africa that does not provide comprehensive, universal health coverage to all of its citizens.

Our nation has fallen far short of its obligation to our children. However, the same persistent champions of older Americans have also been leading champions of children. For example, the late Claude Pepper led the charge for passage of the Younger Americans Act, which was finally adopted by Congress this year. I have consistently battled efforts to reduce funding in education; Social Services Block Grants; the Women, Infants and Children Program. And I was a strong advocate of the Child Care Act and the recently vetoed Family and Medical Leave Act.

I believe that attitudes expressed in articles such as Mr. Samuelson's do not reflect the values of the vast majority of our people. The issues of the elderly and the issues of children are not isolated to their respective age groups. These are family issues. I urge The Post to make this distinction.

MARY ROSE OAKAR U.S. Representative (D-0hio) Washington