Law Firm Attrition Rate by Size: Firms of 1,000+ Lawyers Lose 14.8%

The law firm attrition rate is highest at the largest firms. Sartori & Partners data show that the median firm loses 13.2% of its lawyers a year, to any destination: another firm, a company legal department, government, or a life outside practice. Firms of 1,000+ lawyers lose the most, a median of 14.8%, and firms of 150-399 lawyers the least, 11.9%. The figures cover 525 firms. They count the lawyers who drop off each firm's own website, followed since April 2026 and scaled up to a full year. For a firm leader, that rate is the replacement bill: every lawyer who leaves is a seat to refill, by a lateral hire or by a promotion, and the bill differs sharply by size.

Sorted by size, the median leaving rate runs 14.8% for firms of 1,000+ lawyers, 13.2% for 400-999 lawyers, 11.9% for 150-399 lawyers and 12.7% for firms under 150 lawyers. The order is not a straight line. The rate falls from the largest class to the 150-399 lawyers class, then edges back toward the market figure for the smallest firms, which sit at 12.7% against an all-firm median of 13.2%.

The gap between the largest class and the 150-399 lawyers class is 2.9 points a year. The largest class also sits 1.6 points above the median for all firms. A large firm that plans its hiring on the market-wide rate will under-budget the seats it has to refill each year.

The spread inside the largest class matters as much as its median. The middle half of all 525 firms lose between 10.2% and 16.6% of their lawyers a year. For the 80 firms of 1,000+ lawyers measured, the middle half runs from 13.1% to 18.7%. The lower edge of that range, 13.1%, equals the median for the whole market: three in four large firms lose at least as large a share of their lawyers as the typical firm does.

The top of the range is where the pressure sits. In the Sartori & Partners lateral database, a quarter of firms of 1,000+ lawyers lose 18.7% or more a year, 2.1 points above the upper edge for all firms. No other size class reaches that level: the next highest upper edge is 16.2%, for firms under 150 lawyers.

For a large-firm leader, the useful benchmark is the class, not the market. A rate near 14.8% is ordinary for a firm of that size. A rate above 18.7% puts the firm in the upper quarter of its class for departures, and that is the point to ask which practices and which levels are walking out.

Firms of 150-399 lawyers have the lowest median leaving rate, 11.9%, across 172 firms, the largest group measured. The class is uneven, though. Its middle half runs from 9.2% to 15.7%, a band of 6.5 points. That is wider than the 5.6 points band for firms of 1,000+ lawyers and the 4.7 points band for firms of 400-999 lawyers.

The firms at the upper edge of the 150-399 lawyers class lose 15.7% a year, about level with the 15.6% upper edge of the 400-999 lawyers class. Midsize firms are the most consistent group: a median of 13.2% and a middle half from 10.9% to 15.6%.

For a firm in the 150-399 lawyers class, the low median is a comparison point, not a guarantee. For a firm recruiting from that class, lower turnover means partners there are less often already in conversation with a rival, so an approach takes longer to land and meets fewer competing offers.

High attrition at the largest firms does not mean they are shrinking. Firms of 1,000+ lawyers took 53.6% of the lateral hires whose new firm's size is known, 7,245 lawyers in 12 months. Firms of 400-999 lawyers took 23.4%, firms of 150-399 lawyers 13.3% and firms under 150 lawyers 9.7%.

Sartori & Partners data point to churn rather than decline at the top: the class with the highest leaving rate is also the one that takes the most lateral hires. Most of the people it loses go to other firms. Of lawyers who left a firm between May and October 2026, 86.1% joined another law firm.

For a large firm, attrition is the cost of operating in a fast market, and departures are refilled from the same pool of rivals that departing lawyers join. For a firm of 150-399 lawyers, the lower rate is an asset to protect: that class takes 13.3% of lateral hires, so a lost seat is slower to refill from outside.

Part of the extra loss at the top goes in-house. Since May 2026, 953 lawyers have left a law firm for a company role, or 13.1 for each hundred lateral moves. Of those in-house moves, 59.3% came from firms of 1,000+ lawyers and 24.1% from firms of 400-999 lawyers. Firms under 150 lawyers supplied 4.3%. Associates made up 76.7% of the lawyers who went in-house.

Large firms carry an in-house pull that small firms barely feel, and it lands on the associate bench. A firm of 1,000+ lawyers competes for its associates with rival firms and with corporate employers at the same time; a firm under 150 lawyers mostly competes with other firms.

Benchmark against your size class, not the market. A firm of 1,000+ lawyers below 13.1% is in the lower quarter of its class for departures; one above 18.7% is in the upper quarter. Set the replacement budget from the class median: a firm of 400-999 lawyers should plan for about 13.2% of its lawyers leaving each year, before any growth hiring.

Recruit with patience where attrition is low. Partners at firms of 150-399 lawyers leave less often, 11.9% a year at the median, so build those relationships over quarters, not weeks. At large firms, watch the associate bench: it feeds both rival firms and company legal departments, and replacing it is a standing cost, not a one-off.