The National Symphony Orchestra announced this morning that Christoph Eschenbach will become Conductor Laureate of the orchestra in the 2017-18 season.

In other words, his contract, after what will have been seven seasons as music director of the orchestra and of the Kennedy Center, is not being renewed.

“By 2017 I will have served as Music Director of American orchestras for almost 30 years,” said Eschenbach, who will turn 75 on Friday, said in a press statement, “and it makes sense to step away from these obligations.”

The news means that the National Symphony Orchestra joins the New York Philharmonic in the search for a new music director for the 2017-18 season, after the departure of a music director — there, Alan Gilbert; here, Eschenbach — who was still relatively new to the job.

“I am proud of the legacy I leave and I am deeply grateful to the musicians who have joined with me to create an internationally prominent and unified ensemble,” Eschenbach also said in his official quote. But the nature of that legacy is not entirely certain. In his five years thus far, Eschenbach has overseen the addition of 15 new orchestra members, as well as the ascension of two musicians who were already in the orchestra to first-chair positions. And he led two international tours, almost back to back: one to South America in 2012, and a critically acclaimed one to Europe in 2013, which seemed to promise a new and more prominent future for an orchestra that has always struggled with the perception of not being in the top tier of international ensembles.

Yet it’s open to question whether Eschenbach has actually transformed the orchestra, redefined his post as music director of the Kennedy Center as well as of the NSO, or fully merited one of the highest conductor’s salaries in the United States. The NSO has turned in some fine concerts on his watch, but hasn’t fully shaken its issues with ensemble playing, and its occasional issues in the winds and brass.

And the post of Kennedy Center music director seems, to an outside eye, to be somewhat nominal. He has given 11 recitals with the orchestra’s principals and various star soloists — from the Kennedy Center Chamber Players to two memorable evenings with Matthias Goerne — and two more are scheduled; he has also taken part in five community outreach programs — three coaching sessions at the University of Maryland and two NSO in your Neighborhood events — since 2010. Whether this constitutes real community engagement, or a real redefinition of the music director’s role, is perhaps open to debate. And his role in programming at the Kennedy Center has not been highly visible. If the NSO’s contributions to the upcoming “Iberian Suite” festival are an example, they are notably unimaginative, including a “French composers influenced by Spain” program that’s standard issue around the world.

The NSO is an orchestra that seems always on the verge of taking the next step to a higher level. Eschenbach has brought a certain degree of attention and improvement, but hasn’t had the time fully to redefine the institution, even if it were fully in his power. The orchestra now enters a period of anticipation about the future with which it is all too familiar, looking for the leader who can help it, finally, to reach its full potential.