In Maryland, the state expects to spend $35 million more on education when the age rises to 17 and $54 million more when the age reaches 18 in 2017.
Proponents argued the state will save money in the long run by having a better-educated workforce that will pay more taxes.
Aisha Braveboy, a Democratic delegate who sponsored the measure, also noted that people without a high school diploma are eight times more likely to end up in the state's criminal-justice system.
"From a financial perspective, it makes absolute sense to invest in education instead of incarceration," Braveboy said.
In Illinois, Democratic state Rep. Linda Chapa LaVia sponsored the House legislation to raise the dropout age but now says it was the wrong move.
While calling the Democratic governor a good "team player" for backing the president's proposal, she said raising the age is not realistic considering the state's budget cuts. This week, lawmakers voted to cut $495 million from education, 3.9 percent of the state's funding for schools.
The governor still supports raising the dropout age, spokeswoman Brooke Anderson said.
More than 18,000 Illinois high school students dropped out in the 2010-2011 school year, out of a total of 636,000 students. Legislative staff said they could not reliably estimate the cost to the state if those students were kept in school until 18.
But one group has taken a stab at calculating the cost of allowing those students to drop out. The Chicago-based Alternative Schools Network estimates that each dropout costs Illinois a net lifetime average of about $70,000, while high school graduates contribute a net amount of about $236,000.
For some Illinois lawmakers, the idea of raising the dropout age isn't even worth sending to a commission for study. Sen. David Luechtefeld, a former teacher and high school coach, said he's never talked to a school administrator who thinks raising the age is a good idea.
"Most of the time," Luechtefeld said, "a kid who doesn't want to be in school is a problem for the kids who want to be there."
The Illinois bills are SB3259 and HB4621.
Shannon McFarland can be reached at http://twitter.com/shanmcf
- Photo gallery: Christmas around the world
- Heroes 2014: Ex-CIA officer uses...
- On Christmas, Obama marks end of Afghan combat
- Officer kills armed 18-year-old near Ferguson
- Our six heroes of 2014
- How to help find a cure for Ebola from the...
- NORAD 'tracks' Santa's journey across globe
- Capacity crowds pack screenings of 'The...
- NYPD: Cop ambush killer told passers-by... 15
- Going it alone, Obama rocked the boat... 14
- Obama 's Christmas in Hawaii: Carols,... 12
- Officer kills armed 18-year-old near... 11
- Pope in blistering critique of Vatican... 9
- Key developments in the case of slain... 9
- Killings of 2 New York officers trigger... 6
- Senate, CIA agree torture program was... 6