It pays to get fired-if you are a top executive, that is.

Consider the good things that could happen to Sidney Jay Sheinberg. If the president of MCA Inc. lost his job within a year of the company going through a ''change of control'' -- that is the term MCA uses -- he would take home $16.8 million in cash, or roughly 23 times his normal salary.

Fearful of losing their jobs one way or another, more and more executives are obtaining commitments for such farewell payments as terms of their employment.

While deals as rich as Sheinberg's are unusual, the ones out there can be plenty lucrative.

In theory, ''golden parachutes'' are supposed to ensure that managers put aside selfish concerns about their own employment prospects in the event of a takeover -- and negotiate instead in the best interests of all shareholders.

But golden parachutes can get out of hand.

Sometimes, potential payouts for departing executives are excessive, according to compensation experts.

Other times, companies grant the parachutes to so many employees that the expense of triggering severance agreements actually deters takeovers and may thwart the interests of shareholders.

Again, consider MCA. The severance agreements for MCA's top five officers alone would cost an acquiring firm a minimum of $33.45 million.

And the company has granted 364 other employees parachutes that generally would guarantee them lump-sum payments equivalent to three times their normal salaries, plus benefits and stock.

MCA does not disclose how much these agreements could cost the company.

Assuming, however, that each of these executives earns an average of $75,000 annually, the salary payments alone would amount to $82 million.

Add the stock payments, the cost of the benefits and the money payable to MCA's five top dogs, and you come up with a figure high enough to wipe out a full year of earnings at the Los Angeles-based entertainment company.

Of course, MCA is not the only corporation with severance packages so sweet:

The toymaker Mattel Inc. would give Chief Executive John W. Amerman five times his salary and benefits if he were fired after a change of control. (Amerman earned $1.1 million in 1989.)

Irvine, Calif.-based Fluor Corp. guarantees top executives two to three times annual pay, plus a cash payment to compensate them for lost benefits.

Los Angeles-based National Medical Enterprises would give its top three officers, who together earned $3.7 million in 1989, at least two years' pay, plus stock and incentive awards.

Joseph A. Graziano, senior vice president and chief financial officer of Apple Computer Inc. in Cupertino, Calif., would get $2.4 million if he were fired, and Apple's Senior Vice President Delbert W. Yocam would get $1.6 million.

More lucrative still is Armand Hammer's severance agreement. Occidental Petroleum Corp.'s 92-year-old chief executive can quit as much as a year after ''he has knowledge of the change'' of corporate control, or if there is a major breach of his employment agreement, according to a company proxy statement.

He is guaranteed his salary, bonus (adjusted for cost-of-living increases), perquisites, employee benefits, life insurance benefits and pension and long-term incentive benefits until the end of his employment agreement.

His employment agreement, which runs until 1998, is automatically extended for seven years beyond any point after Feb. 1, 1991. In short, it always has seven years to go.

The estimated value of Hammer's severance deal exceeds $16 million.

Moreover, if the Internal Revenue Service deems payments to Hammer ''excessive'' and imposes an excise tax on any part of the payout, Occidental has agreed to pay that tax, too.

The odds that the IRS would impose such a tax are fairly good. The agency has said it considers any payment exceeding three times annual pay and perks excessive enough to warrant a 20 percent tax.

''It is not illegal to give a huge parachute, but it is a slap in the face to shareholders,'' Gary Hourihan, president of Strategic Compensation Associates in Los Angeles, said of deals such as Hammer's.

Shareholders are no longer turning the other cheek.

Occidental shareholders, for example, are so incensed about a variety of arrangements between Hammer and Occidental that they have filed a series of class-action lawsuits against the company.

One suit alleges that the compensation payable to Hammer and other executive officers is ''excessive, unreasonable and a waste of corporate assets.''

Moreover, the suit charges that the board breached its duty of guiding the company in a responsible manner by approving the transactions.

At Lockheed Corp., some shareholders tried to force a vote on whether to eliminate the golden parachute. Management of the aerospace company headed off the effort, but there is no assurance dissident stockholders will not try again.

Lockheed's plan would pay top officers three times base salary, plus benefits. For Chief Executive Daniel Tellep, who earned $763,943 (not counting benefits) in 1989, the value of the package was $5.8 million, according to the company's proxy statement.

The United Shareholders Association, a Washington-based shareholder rights group founded by corporate raider T. Boone Pickens Jr., sponsored proposals this year that would require golden parachute plans to be submitted to non-binding shareholder votes at four companies, including San Francisco-based Transamerica Corp. and Great Western Financial Corp. of Beverly Hills. Both proposals failed to garner approval of a majority of shareholders.

There is little chance that many golden parachute plans will be phased out.

BankAmerica Corp. of San Francisco eliminated its golden parachutes this year, declaring the protection ''no longer necessary'' now that the company has regained its health and thus is no longer threatened by a hostile takeover -- as it was several years ago.

But dozens of other firms plan to institute such plans, according to Fred Whittlesey, senior manager of KPMG Peat Marwick's Los Angeles compensation consulting group.

The reason? Executives are highly competitive with one another and tend to believe that if their peers have lucrative severance agreements, they should, too.

The problem is exacerbated by compensation surveys, which reveal the average terms and value of these deals.

Some companies have decided they want to be ''in the 75th percentile'' on all issues of pay, compensation experts say. That, of course, boosts the pay scale for everyone the next year.

''There is a competitive pressure that makes {parachute} contracts more and more prevalent and payouts fatter and fatter,'' Whittlesey said.

''I do some work with some very small companies and even they are concerned about a change in control," he said. "A mentality has been created where everyone wants this benefit.''