Today’s 9-year-olds are significantly better readers than 9-year-olds were a half-century ago. Today’s 13-year-olds are not.

That’s the troubling lesson from the latest long-term trend data from the National Assessment of Educational Progress. The results suggest that America has made real progress helping young children build foundational skills — the problem is that too many students stop building on those gains as they move into adolescence.

Since the 1970s, the NAEP’s long-term trend test has looked at reading and math performance among American 9- and 13-year-olds. The idea is straightforward and age-appropriate, dealing with fundamental skills. Can a child find the average of three numbers? Can they find the main idea in a story passage?

On the one hand, the latest batch of NAEP long-term national data shows 9-year-olds are making progress in reading and math compared to 2022, a welcome sign showing our youngest learners are on the right track.

While 9-year-olds show broad long-term progress, 13-year-olds show little overall progress. Only the highest-performing adolescent readers outperform their peers from the 1970s. Most other students show little measurable change.

This is a problem the adults in charge need to reconcile.

The pandemic did not create this problem, but it appears to have made an existing one worse. Before COVID hit, 13-year-olds had made modest gains compared with the 1970s, though those gains lagged well behind the progress made by younger students. Then came school closures and learning disruptions that hit today’s 13-year-olds at a particularly vulnerable age. The result was a sharp decline across the achievement spectrum, with scores falling at every reported percentile…