July 1, 1991, will either see home sales screech to a halt or usher in a new era of integrity in real estate appraising -- depending on which real estate industry spokesman you talk to.

Starting on that date, the nation's 200,000 to 400,000 appraisers must prove their competency under a new federal appraisal law. They must complete at least 75 hours of appraisal education, document two years of experience and pass a state-administered test.

But 16 states and the District of Columbia still have not enacted their own laws to implement the federal law passed last August. What's more, federal regulators may challenge the adequacy of laws enacted by a handful of other states. And all the states still have to put a regulatory structure in place to license appraisers or certify those appraisers with more skill and experience.

In Maryland and Virginia, for example, no members have been named to the appraiser commissions authorized in April by the two states' legislatures. Nor has either state issued regulations, approved appraiser courses, prepared and administered tests, awarded any licenses or certificates or set disciplinary measures.

Given all that's left to do, the National Association of Realtors (NAR) warned during a congressional hearing last week, the July 1991 deadline will be impossible to meet.

Eight national appraisal organizations, however, say that preparations are on schedule and that any delays will undermine the momentum of appraisal reform.

Appraisers who fail to get licensed or certified in time will not be allowed to do appraisals with any connection to the federal government. That covers most appraisals, industry officials say, because most appraisals are for purchases that involve a federally insured lender or the government-sponsored secondary mortgage market.

The appraisal industry has borne part of the blame for the bill -- estimated at $300 billion over 10 years -- that taxpayers will foot to rescue the savings and loan industry. The largely unregulated appraisers, critics say, exacerbated the problem with faulty appraisals overstating the value of properties and, in some cases, by doing outright fraudulent appraisals.

Earl Espeseth, a Madison, Wis., real estate broker and an NAR spokesman on the appraisal issue, predicted nationwide shortages of qualified appraisers next July that will lead to "massive delays and disruptions in real estate transactions across the United States."

Stephen Driesler, NAR's chief lobbyist, said home sales could take three times as long to close because of appraiser shortages next summer. A written appraisal, he said, is a requirement for virtually all mortgage financing. Appraisals, which now costs about $250, will likely rise in price as a result of appraiser shortages that will be caused by the new law, he said.

To head off the "catastrophe" that it sees brewing, the NAR wants the deadline extended by one to two years, Driesler said. During that time, under NAR's proposal, appraisers would have to pass a test, but the education and experience requirements wouldn't be as stiff as those in the new federal law, he said.

But the eight appraiser organizations, including the American Institute of Real Estate Appraisers, which severed its 58-year relationship with the NAR in April, are confident that there is "ample time" for all 50 states to test and license enough appraisers, said Ritch LeGrand, spokesman for the coalition and president of the Society of Real Estate Appraisers.

Donald E. Kelly, chief legislative counsel for LeGrand's organization, said the eight appraisal groups have already conferred professional designations similar to the federal standards on 80,000 appraisers. With each appraiser performing an average 300 appraisals a year, Kelly added, there will be more than enough to handle the 4.2 million residential sales each year and home equity and refinance demands.

In a worst-case situation, LeGrand said, the federal law also has some give. Regulators can delay implementation of the law for six months either nationally or state by states, and can waive the certification and licensing requirements indefinitely for states that prove they face a shortage.

LeGrand said those who want to delay enactment of the new federal standards either misunderstand the regulators' latitude or are "simply trying to buy time to subvert the objectives of the law."

He said 19 additional states have approved laws since January, bringing the total to 34. By the end of the year, he expects 40 states to have laws in place. LeGrand said talks with state officials have convinced him there are no insurmountable obstacles to meeting the July 1991 deadline.

However, LeGrand said some state laws may need to be revised to comply with the federal law, which encourages states to make the appraisal commission independent of the state's real estate sales regulator.

The federal law also discourages states from requiring would-be appraisers to have a real estate agent's or broker's license, as Florida and Texas do. It also bans exempting current appraisers from new standards.

Federal regulators appear ready to give a bit. Mary C. Short, a member of the federal regulatory committee representing the five federal agencies with an interest in real estate appraisals, said she and the other regulatory committee members "do not want to get too hard-nosed about this."

For example, Short said, federal regulators might be willing to let some states temporarily qualify appraisers who have enough experience and who pass a competency test. But they would eventually have to meet the educational requirement, she said.

Short said the subcommittee also is "feeling better" about the prospect that a national six-month extension would not be needed. A few months ago, the panel thought the extension would be necessary.

Officials in Virginia and Maryland do not anticipate any problems with meeting the July 1991 deadline.

Virginia expects to begin testing and licensing its appraisers, who number between 3,500 and to 5,000, in January, said Alvin Whitley, a spokesman for the Virginia Department of Commerce.

Judy Donaldson, deputy commissioner of Maryland's division of occupational and professional licensing, said Maryland will not start processing its 3,000 to 5,000 appraisers until closer to the deadline.

The Realtors and the appraiser coalition also are at odds over what types of residential transactions should require a licensed appraiser or the more highly qualified certified appraiser. Federal law permits licensed appraisers to perform single-family home appraisals on properties worth less than $1 million provided the transactions are not "complex."

The NAR would like federal regulators to decree that virtually all residential transactions qualify as routine unless the lender says otherwise. The appraiser groups, however, would like to start with the presumption that all residential deals require a certified appraiser unless the lender decides the transaction is a simple one.