Eight of America’s richest reside in Maryland, representing a combined $20 billion in net worth, according to the Forbes 400 list of wealthiest Americans released Monday.

Maryland’s richest and their net worths are: Ted Lerner ($4 billion, real estate), Mitchell Rales ($3.5 billion, manufacturing), David Rubenstein ($2.6 billion, private equity), Bernard Saul II ($2.2 billion, banking, real estate), Stephen Bisciotti ($2.1 billion, staffing, football), Richard Marriott ($2 billion, hotels), Bill Marriott Jr. ($1.9 billion, hotels) and Kevin Plank ($1.7 billion, athletic wear).

While none of the eight made the top 100 — Maryland’s richest man, Ted Lerner, is at 110 — all eight gained wealth in the past year, and five of them are self-made billionaires.

Benjamin Orr, policy analyst for the Maryland Budget and Tax Policy Institute, said the rankings bode well for the state and rebut the idea that rich residents are fleeing the state because of taxes.

“This idea that the ultra-rich are fleeing the state … is just not true,” said Orr. “The fact that the names on the list remain stable is a positive indicator.”

Nine Marylanders made the Forbes 400 list last year. The one who did not return was Dan Snyder, owner of the Washington Redskins, who is now No. 426 in the United States. Although he made $100 million in the past year, that was not enough to keep pace with the current 400, who all have a net worth of $1.3 billion or more.

Maryland, with 1.87 percent of the United States population, takes up 2 percent of the Forbes 400, but Christopher Summers, founder and president of the Maryland Public Policy Institute, said the eight do not owe their wealth to state policies.

“I think what it’s telling of Maryland policy is that it could have a lot more from Maryland on that list,” said Summers. “It does push many people out the state that aren’t at that income level yet.”

Recent increases in sales tax and gas tax have little effect on billionaires, said Summers, but may motivate future billionaires making six-figure salaries into other states. He also blamed Maryland’s estate and inheritance taxes for being unwelcoming to older wealthy people.

Summers pointed to IRS records as proof that Marylanders are leaving because of changes in tax policy.

A map synthesizing such records, compiled by the Tax Foundation, a nonpartisan tax research group, showed that Maryland lost net personal income of $5.5 billion between 2000 and 2010 due to a net loss of about 66,000 residents to other states in the U.S. Only seven states lost more net income during that time. The residents who left were most likely to go to Florida, Pennsylvania, North Carolina or West Virginia.

A variety of factors, including taxes, could have played into this migration, said Elizabeth Malm, a Tax Foundation economist.

“I don’t think you can say confidently that [taxes are] not part of that equation,” Malm said, but “I don’t think people are going to just pick up and move immediately if there’s an increase in the tax rate.”

Determining the reasons behind this relocation would require a state-by-state analysis, she said, but taxes were likely one of many factors playing into Maryland’s loss of personal income.

A study by the Center on Budget and Policy Priorities made a similar assertion to Malm’s — that tax rates can neither take the primary blame for migration nor evade all blame. It also said that housing prices tend to be a greater motivation for migration than tax rates.

The study points to Florida as an example — it gained the most net personal income from 2000 to 2010, according to the Tax Foundation. Some tied this statistic to a nonexistent state income tax, but the Center on Budget and Policy Priorities study pointed out that Florida actually lost population from about 2007 to 2009, following a sharp rise in housing prices in the state.

While some may move to escape Maryland’s tax rates and others may stay in spite of them, still others may be able and willing to pay, said Orr, to ensure the quality of state resources.

“I think people recognize what they get in return,” he said, referring to infrastructure that includes schools and transportation. “We need to increase investments in these things.”