Who Hires From Whom by Firm Size: 39.0% of Moves Stay in Big Law

Two lateral moves in five (39.0%) stay inside big law. Sartori & Partners data show that 4,313 lawyers moved from one firm of 1,000+ lawyers to another in the 12 months to October 2026, out of 11,058 moves where the size of both the old and the new firm is known. The next two flows are the lateral moves between big law and midsize firms: 1,200 lawyers went up from a firm of 400-999 lawyers to a firm of 1,000+ lawyers, and 1,117 went the other way. Here big law means firms of 1,000+ lawyers and midsize means firms of 400-999 lawyers. For a firm planning its next hire, the useful question is not which class is growing but which class it can realistically recruit from, and which class is recruiting its own people.

The largest class behaves more like a closed circuit than a magnet. Of the 6,444 lawyers who joined a firm of 1,000+ lawyers from a firm of known size, 4,313 came from another firm in the same class. Midsize firms supplied 1,200, firms under 150 lawyers 432 and the 150-399 lawyers class 499. Big law hired 3.6 times as many lawyers from its own class as from the 400-999 lawyers class, its second source.

Exits mirror entries. Of the 6,341 lawyers who left a big-law firm for another firm of known size, 4,313 stayed in the class, 1,117 joined a midsize firm, 477 joined a firm under 150 lawyers and 434 joined the 150-399 lawyers class. A lawyer who leaves a large platform usually lands on another large platform.

The size of the class explains part of this. In the Sartori & Partners lateral database, firms of 1,000+ lawyers took 53.6% of all lateral arrivals where the hiring firm's size is known, against 23.4% for the 400-999 lawyers class. That count is wider than the flows, which also need the size of the firm left, so the two sets of figures sit side by side here and are never added together.

For a big-law hiring partner, the candidate pool is mostly the firm's direct competitors, and an offer often meets a counter-offer from a firm of the same scale. The midsize class is the second pool, with 1,200 lawyers who moved up in a year, and it is the one where a large platform's reach still counts as an argument.

The exchange between the two largest classes is close to even. In 12 months, 1,200 lawyers moved from a firm of 400-999 lawyers up to a firm of 1,000+ lawyers; 1,117 moved from big law to a midsize firm. The gap is 83 lawyers, or 1.1 moves up for each move down. On balance the midsize class feeds the largest one, but for nearly every lawyer it sends up, it takes one back.

Movement inside the midsize class is thin. Only 626 lawyers moved between two firms of 400-999 lawyers, 5.7% of all moves with both sizes known, against 39.0% between two big-law firms. Of the 2,339 lawyers who left a midsize firm for another firm of known size, 1,200 went up to big law and 626 went to a peer.

For a midsize firm, the main competitor for its own lawyers is the class above, not the firm across the street. A retention plan built around matching peer offers misses where most departing lawyers go. The same channel works in reverse: big law is also where a midsize firm's next hires are most likely to come from.

Of the 2,505 lawyers who joined a firm of 400-999 lawyers from a firm of known size, 1,117 came from big law, 408 from firms under 150 lawyers, 626 from midsize peers and 354 from the 150-399 lawyers class. Big-law alumni outnumbered peer hires 1.8 to one.

The class grows on what it takes from smaller firms, not on its trade with big law. It hired 408 lawyers from firms under 150 lawyers and sent back 281; it took 354 from the 150-399 lawyers class and returned 232. In total, 2,505 lawyers joined midsize firms from firms of known size and 2,339 left them for one.

For a midsize firm, a search brief aimed at associates and counsel in firms of 1,000+ lawyers is the main channel, not a fallback. The pitch that works there is the platform difference itself: a smaller partnership, a broader role, a different path to partner.

Firms of 150-399 lawyers took in 1,095 lawyers from firms of known size and sent out 1,201. Their largest single source was big law, with 434 moves, ahead of the midsize class at 232 and firms under 150 lawyers at 225. Their departures went up the size scale: 499 to firms of 1,000+ lawyers and 354 to the midsize class, while only 204 moved between two firms of this size.

Below them, firms under 150 lawyers sent 1,177 lawyers to other firms and received 1,014, a net export that has its own report. For a firm of 150-399 lawyers the recruiting map starts above it: big-law alumni are the first pool, well ahead of small practices, and the lawyers it trains are approached by larger platforms.

Lateral flows are one way a class fills its partnership; promotions are the other. Promotion figures run to May 2026, the last complete month, so they cover the 12 months to May 2026 (June 2025 to May 2026), not the lateral window that ends in October 2026: the comparison below is between each class's share of the two totals, not between the same months. Firms of 1,000+ lawyers made 1,474 promotions to partner in the 12 months to May 2026, 49.9% of the market total, below their 53.6% share of lateral arrivals. The 400-999 lawyers class made 871, or 29.5%, above its 23.4% share of lateral arrivals. Firms of 150-399 lawyers made 14.9% of promotions against 13.3% of arrivals, and firms under 150 lawyers 5.5% against 9.7%.

Smaller classes also promote a little earlier. At firms of 150-399 lawyers, 27.1% of partners promoted in the last 5 years made it within eight years of starting practice, against 21.8% at firms of 1,000+ lawyers, while the median stays at 10.0 years in every class. A midsize firm therefore runs two pipelines at once: it grows more partners at home than its lateral share suggests and buys experienced lawyers from big law. Big law leans more on the lateral market, mostly on its own class.

If you lead a firm of 1,000+ lawyers, plan searches as contests with peers: 4,313 of the 6,444 moves into your class from firms of known size came from it, so expect matched offers. The midsize class is your second pool, with 1,200 lawyers moving up in a year; reach it with a clear case for scale.

If you lead a firm of 400-999 lawyers, treat big law as both your main source and your main risk. You hired 1,117 lawyers from it and lost 1,200 to it, so a retention review should look upward first. Your own promotions, 29.5% of the market total in the 12 months to May 2026, are a selling point to big-law associates who want a visible route to partner.

If you lead a firm of 150-399 lawyers, your largest source is big law, which sent you 434 lawyers; smaller practices sent 225. Sartori & Partners figures come from public law-firm announcements, firm websites and professional profiles, checked monthly, and count each move once, by the size of the firm left and the firm joined.