BALTIMORE, June 3 -- This year, McCoy has received $102,500 for his work in the state capital, not counting expenses. This time he was a rookie lobbyist.

And McCoy is not the only lobbyist doing well. Officials at the Maryland Ethics Commission have not yet received all of the lobbyist disclosure reports from the recently completed legislative session, but all indications are that this will be another record year for lobbying -- and feeding -- the legislators.

The amount spent on cajoling, educating and caring for Maryland's 188 legislators has increased every year since the commission began administering the filing program in 1979, and the total has increased from $2.9 million then to nearly $6.8 million in 1986.

The reports show that, just as there is a ruling clique of legislators, there is a ruling class of lobbyists. Those who make the most money and represent the most influential clients rarely change.

McCoy is a newcomer to the crowd, and said he likes it just fine. McCoy told his colleagues on his last night in the General Assembly that his decision to leave was an "economic decision," and he added today, "this has been a very good year for me." Another former legislator, Frederick C. Rummage of Prince George's County, has also found it profitable on the outside, earning $69,000 this year, including $30,000 for representing the Prince George's County government.

McCoy represented the trial lawyers association (for $35,000) and a group of lawyers and others opposed to changes in the worker's compensation laws (for $20,000) with only limited success.

He received $40,000 from a coalition of some of the region's largest retail department stores to successfully seek a repeal of Maryland's blue laws. Marylanders for Blue Law Repeal spent more than $55,000 overall lobbying the legislature on the effort.

McCoy's earnings will most likely elevate him into the financial top 10 of the state's more than 600 registered lobbyists. The vast majority are concerned with only one issue, but 26 lobbyists in 1986 had four or more employers, according to the ethics commission, and six received more than $100,000 in fees last year.

At the top of the list, financially, is Annapolis lawyer Bruce Bereano, a 42-year-old former legislative aide who is breaking records each year for what he receives to lobby the legislature. Bereano also seems to be making a game of it, offering reporters his own precise count of the money he has received from the 58 clients he represented.

The total is $551,493 for his efforts so far this year, more than Bereano made in all of 1986. He also reported spending $64,910 of his clients' money on meals and gifts for officials. Bereano, who usually represents at least twice as many clients during the 90-day legislative session as others take on, made just under $425,000 during last year's session.

His largest fee, $47,246, came from Medical Mutual Liability Insurance Society, which hired a number of lobbyists to work with Gov. William Donald Schaefer to persuade the legislature to change laws governing victims' rights to sue in exchange for lower medical malpractice insurance rates. Bereano also received $47,000 from The Tobacco Institute to fight movements to pass no-smoking laws.

The other top earners remain virtually unchanged from last year. Baltimore lawyer Ira C. Cooke earned more than $200,000 representing 19 clients, while James J. Doyle Jr., Franklin Goldstein, George N. Manis, Devin Doolan and Joseph J. Schwartz III all made more than $100,000. Goldstein apparently received the top fee; he earned more than $78,000 from Citibank of Maryland and its Choice credit card operation.

And it is men who pull down the top salaries. Of the 18 lobbyists with the highest earnings in 1986, only two were women.