The National Collegiate Athletic Association has acknowledged what everyone always knew — that not all college sports programs are the same.

At a meeting in Indianapolis on Thursday, the N.C.A.A. Division I board of directors voted to give the five richest conferences greater autonomy, including the right to award cost-of-living stipends, improve health insurance benefits and loosen the rules on player contact with agents. The so-called Big 5 — the Southeastern Conference, the Atlantic Coast Conference, the Pacific-12, the Big Ten and the Big 12 — will also be able to help players’ families in ways they cannot now, like paying for their travel to see postseason games.

N.C.A.A. member institutions could still override the legislation, but this is unlikely. Under the new rules, the rich will inevitably get richer, able to recruit the best new players, win more end-of-season bowl games and amass larger television audiences and greater revenues. The Big 5 were already the aristocrats of the college sports world, but now that status is official and the gap between the elite and the rest will almost certainly widen.

On the upside, athletes who play for one of the 65 universities in the Big 5 will also benefit, if modestly. They have not won the right to negotiate salaries, or to share in the considerable wealth generated from commercial licensing agreements. But some will receive a few thousand dollars more per year to cover the “full cost of attendance,” and they will gain better medical coverage. That’s better than window dressing but well short of life changing. On the losing side are smaller schools that will have a harder time competing for top talent and the purists who cling to the amateur ideal.