It touches everyone, when a careless father will not pay his child support. Mother and child have a lower living standard; the state (read: taxpayers) may have to put the family on welfare; and it costs even more public money to find the father and force him to pay.

In the past, many states kept their dad-bashing to a minimum -- going after only those delinquent fathers whose families wound up on welfare. But a law just signed by President Reagan requires states to help all mothers who are not paid their court-ordered child support, whether they're on welfare or not.

But like many good things, it will be a long time coming. The new law doesn't take effect until Oct. 1, 1985, and many states will have to change state law to conform to the new federal procedures. In some states, it will be up to two years before you reap the benefits of the change, according to Dan Copeland, Alaska's director of child-support enforcement. "We handle the desperate," he says, "and unfortunately, the child-support programs won't improve as fast as mothers hope." (Some mothers don't meet child-support payments either, but the vast majority of holdouts are dads.)

A problem for many states is that the federal government is increasing the reach of their programs without providing the money needed to do it right. "The real message of the federal government comes from funding," Copeland says, and the law calls for the federal share of state expenses to drop in 1988 and drop again in 1990. A change in the incentive-payment formula may also reduce funding in some states.

Fortunately for many frantic women, some states already perform one or more of the child-support collection services newly ordered at the national level. In those states, the program could expand. When the law is fully effective, this is what parents can expect:

*More help from more people. Not only will non-welfare mothers be included in all state child-support collection programs, states will also have to give equal enforcement time to collection orders from out-of-state -- ending the ease with which fathers can cross some state lines and avoid child support. The states will also help mothers collect their alimony, if it is paid together with child support and if the child lives with the mother. (No help will be given for alimony when no children are involved.)

*More effective collection efforts. States must speed up their procedures for getting and enforcing child-support orders. They will also be required to withhold child-support payments from a delinquent's wages, if the value of his payments falls more than a month behind. The father can contest withholding if he thinks it shouldn't apply to him. If he loses, the state can withhold up to 55 percent of his disposable income if he has a second family and 65 percent if he doesn't.

At their discretion, states also can withhold state-tax refunds due delinquent dads; file to block their federal tax refunds; withhold child-support payments from other forms of income, including pensions and dividends; put liens against their real estate or other personal property; require habitual delinquents to post a bond guaranteeing future payments; and give credit bureaus, if they ask, the names of people who owe child support in amounts under $1,000 (it's mandatory that larger amounts be disclosed). They can also decide to establish paternity and collect payments from the father anytime before the child reaches age 18. Right now, the statute of limitations runs out on paternity suits, in some states, when the child reaches age three or four.

One hitch in all this good work may be the attitude of some state judges. A stubborn judge may resist federal direction, Copeland says. His attitude is, "This is my court, and we're going to do child support my way." Federal law orders him to provide for wage withholding, like it or not; but he could dally in getting out of the order, and might refuse to order non-mandatory collection procedures.

Another hitch is money. The states will have to come up with larger budgets to fulfill their expanded child-support collection mission, or else serve fewer people than need help.

The new law charts the right direction. But for a lot of penniless mothers, relief is still a thousand miles away.