Nearly 90 percent of mortgaged homes in the United States had equity in the first quarter of 2015, according to a study by the financial company CoreLogic.

The analysis said there are approximately 50 million mortgaged homes, and that 89.9 percent of them—or 44.9 million—have equity. This indicates that a home's appraised value exceeds the outstanding balance on the mortgage.

CoreLogic says increasing home prices led to 254,000 homes regaining equity in the first quarter of 2015. The company estimates that another 1 million homes would regain equity if home prices increase by 5 percent.

"Many homeowners are emerging from the negative equity trap, which bodes well for a continued recovery in the housing market," said Anand Nallathambi, president and CEO of CoreLogic. "With the economy improving and homeowners building equity, albeit slowly, the potential exists for an increase in housing stock available for sale, which would ease the current imbalance in supply and demand."

An estimated 5.1 million homes, or 10.2 percent of mortgaged residences, had negative equity. In this designation, also referred to as an "underwater" or "upside down" mortgage, a homeowner owes more on a mortgage than a home is worth.

CoreLogic says the aggregate value of negative equity homes in the United States was $337.4 billion in the first quarter of 2015. This marked a decrease from the fourth quarter of 2014, when the value of negative equity properties totaled $349.1 billion.

About 3.1 million borrowers with negative equity held first liens only, without any home equity loans. On average, these borrowers had a $229,000 balance and owed $58,000 more than what the home was worth.

The remaining 2 million borrowers with negative equity had both first and second liens. This group had an average balance of $295,000 and owed $78,000 more on a mortgage than the home's appraised value.

Of the homes with equity, CoreLogic says 19.4 percent—or 9.7 million homes—were considered to be "under-equitied." This term refers to properties where the homeowners have built up less than 20 percent equity in the property.

Another 2.7 percent of homes, about 1.3 million, were considered to have near-negative equity of 5 percent or less. CoreLogic says these homes are most in risk of losing equity in the event of a significant decrease in home prices.

On average, the loan-to-value ratio for a mortgaged home was 58.8 percent. Only 2 percent, or 1 million homes, had a loan-to-value ratio of 100 to 105 percent. Another 1.9 million homes, or 3.8 percent of mortgaged properties, had a loan-to-value ratio of 125 percent or more.

More expensive homes were more likely to have equity. While 85 percent of properties valued under $200,000 had equity, this share rose to 94 percent for homes valued at more than $200,000.

Thirteen states had a higher negative equity share than the U.S. average, including Connecticut and Rhode Island. The five states with the highest shares of negative equity homes made up 31.4 percent of the nation's negative equity.

In Connecticut, 88 percent of 838,000 mortgaged homes had equity in the first quarter of 2015 and 12 percent had negative equity. Of the homes with equity, 3.3 percent were considered to have near-negative equity. The average loan-to-value ratio was 58.5 percent.

In Rhode Island, 84.3 percent of 235,000 mortgaged homes had equity and 15.7 percent had negative equity. The near-negative equity share stood at 2.9 percent. The average loan-to-value ratio was 60.8 percent.

Rhode Island had the fifth highest negative equity share in the United States in the first quarter of 2015. The four states with the highest share of negative equity homes were Nevada (23.1 percent), Florida (21.2 percent), Illinois (16.8 percent), and Arizona (16.8 percent).

Texas had the highest share of homes with equity at 97.7 percent, followed by Hawaii at 96.9 percent. Other states with the highest share of homes with equity included Alaska (96.8 percent), Montana (96.8 percent), and North Dakota (96.2 percent).

Seven states, including Maine and Vermont, did not have sufficient data to be included in the study.

The Houston and Dallas metro areas in Texas had the highest share of homes with equity at 97.9 percent and 97.6 percent, respectively. Other metro areas with high shares of home equity included Denver, Colorado at 97.1 percent; Portland, Oregon at 97 percent; and Anaheim, California at 97 percent.

The metro area in Tampa, Fla., had the highest percentage of negative equity homes at 23.1 percent. This was followed by Chicago, Ill. at 19.1 percent; Phoenix, Ariz. at 16.9 percent; Riverside, Calif., at 13.9 percent; and Warren, Michigan at 13.4 percent.

CoreLogic says the mortgaged properties included in the study represent about 85 percent of all mortgaged homes in the United States.