The alien amnesty deadline should be extended. ... despite the good job the INS has done

THE congressional immigration legalization program gives all eligible aliens one year to apply for legal status, yes or no? No.

Congress fashioned four separate legalization programs. One is for people illegally in the United States since Jan. 1, 1972. There is no deadline for their applications. The second is for agricultural workers who worked in the US for specified periods during 1984, 1985, or '86. They have until Dec. 1, 1988, to apply.

A third is for Cubans and Haitians, for whom federal assistance but not legal status has been granted since 1981. They have until Nov. 6, 1988, to apply. Finally, there is the general legalization for all other illegal aliens who can show continuous residence here since Jan. 1, 1982. Their application period ends May 4, unless Congress extends the deadline.

When Congress mandated legalization, its intent was both altruistic - authorizing legal status for people who ``have contributed for years toward our economic and social well-being'' - and pragmatic - strengthening future immigration enforcement under employer sanctions by allowing the government ``to target its enforcement efforts on new flows of undocumented aliens.''

To achieve these objectives, the maximum possible number of those eligible must apply. That number is in the range of 1.8 to 2.6 million for the general legalization, the biggest and best known of the programs. So far, just under 1.15 million have come forward. A late surge may bring the number to 1.3 million - or 500,000 people short of the low point of the range.

To ``meet our goal of every possible person who's eligible,'' the Immigration and Naturalization Service (INS) has announced it will now allow an additional 60 days for documentation to be submitted as long as a skeletal application is filed by the May 4 deadline. It will also reimburse assistance organizations and states for referring new applicants.

These steps cap an already exemplary record of efficient application processing, adjustments in regulations where needed, evening and weekend hours, and attractive offices staffed with courteous, sympathetic personnel.

Even so, INS's research shows that while immigrant groups are aware of the legalization program, many individuals wrongly believe they are ineligible. An aggressive publicity campaign to overcome these misimpressions has not yet generated a real rise in application rates.

So it is curious that INS is actively campaigning against legislation that would do the one thing it cannot: extend the life of the program. Officials argue that extension is not needed, because more people have already applied than in any other nation's program. They assert that extension requires concomitant adjustments in the enforcement provisions of the immigration reform law. Finally, they say that an extension would be confusing and would require a congressional appropriation to cover costs.

These arguments do not hold up. More people have applied here than elsewhere because there were more here to start with. Extension does not presume a change in the equation upon which immigration reform was based; it simply allots more time to accomplish what was already bargained for.

A later deadline would be no less confusing than the numerous changes in eligibility and documentation requirements which have (properly) been made all along to improve the program. And cost factors can be addressed by shifting personnel and consolidating offices, as INS has also done all along, to comply with the congressional requirement that legalization be self-financing.

The only real issue before Congress is whether additional time will generate a substantially larger number of applications. No one can say for certain. What can be said is that legalization has been a massive undertaking that represents a great leap into the unknown for the government, assistance organizations, and eligible aliens alike.

Important elements, such as court rulings on key issues in the government's regulations and effective community outreach, are only now falling into place. And even if another half million or more apply, the remaining illegal population in the country will still be about twice the number legalized, given the eligibility restrictions Congress set. So it is strongly in our interest to ensure that the maximum number of those who can qualify do so. A deadline is necessary. But it should err on the side of inclusion.

There is no ``right'' period of time to ensure a successful program. Other countries' programs have ranged from two months to two years, most having extended the time initially designated. In the US case, the different application deadlines among the discrete programs are arbitrary, creatures of the chaotic nature of the legislative process. If Congress was comfortable allowing some to have until Dec. 1, 1988, to gain legal status, it should be willing to tender the same offer to all.

Should Congress correct itself now? Yes!

Doris M. Meissner, senior associate at the Carnegie Endowment for International Peace, was formerly acting commissioner of the INS.