The percentage of Latinos and African Americans who signed up for subsidized health coverage through California’s insurance exchange increased modestly during the second annual open enrollment period, officials announced Thursday.

About 37 percent of subsidized enrollees are Latino, up from 31 percent during the first enrollment period ending in March 2014, according to data released by Covered California. About 4 percent are African American, up from 3 percent last year. The numbers, released by Covered California during its monthly board meeting, include only those enrollees eligible for subsidies who responded to questions about their race or ethnicity.

Covered California faced criticism last year for failing to sign up enough Latinos, particularly those who spoke primarily Spanish. The insurance exchange launched a dedicated, bilingual campaign – both in the media and on-the-ground to educate and enroll more Latino consumers.

Covered California Executive Director Peter Lee said the increases in both Latino and African American enrollment show the targeted efforts were successful.

“This is a reflection of not just the advertising and marketing … but very good outreach in communities throughout the state,” Lee said.

Advocates praised the exchange for the more diverse population of enrollees. The percentages enrolled roughly match the proportion believed to be eligible for subsidized coverage in the population at large.

“It’s good that Covered California has reached further into Latino communities, but there’s more to do,” Anthony Wright, executive director of the nonprofit Health Access California, said in a statement.

Wright and others said the next challenge is ensuring that Californians don’t drop coverage when they experience life changes, such as moving or switching jobs.

The exchange also saw a jump in the percentage of younger enrollees. About 34 percent of new enrollees are between 18 and 34, compared to 29 percent of enrollees last year.

Younger enrollees are critical to balancing out the older, sicker population that signed up for coverage right away.

Open enrollment ran from November until Feb. 22 for most people. Those who did not know about the tax penalty for not having insurance can sign up until the end of April.

Altogether, more than 495,000 people signed up for private health coverage in the second open enrollment, including about 88 percent who were eligible for federal subsidies. An additional 779,000 people signed up for Medi-Cal, the program for poor and disabled Californians.