How Long to Make Partner in Tax: A Slower Finish, More Buying

Ask how long to make partner in tax and the honest answer is: as long as anywhere else for most associates, and longer for the rest. Sartori & Partners data show that 72.4% of tax partners promoted in the 5 years to May 2026 made it within 12 years of practice, against 75.4% across all practices. The average tax promotion came after 11.3 years, the market average after 11.1 years. The gap sits at the back of the track, and it changes how firms staff the practice. In the 12 months to May 2026 firms promoted 145 tax lawyers to partner, or 0.58 for each lateral tax partner they hired in the same months. Across the market the figure is 0.79. For a firm leader, the two numbers belong together: a long finish on the internal track is one reason tax seats get filled from outside.

The early track is no different from the market. Within 8 years of practice, 23.1% of tax partners had been promoted, against 23.2% across all practices. The fastest quarter of tax promotions came by 9.0 years, the same point as the market's 9.0 years, and the median tax partner was promoted after 10.0 years, level with the market median of 10.0 years.

The difference opens in the later years. The slowest quarter of tax partners waited 13.0 years or more, where the market's slowest quarter starts at 12.0 years: 1 more year at the back of the queue. That tail is what lifts the tax average 0.2 years above the market average and leaves the share promoted within 12 years 3.0 points below it. The tax figures rest on 537 promotions, the market figures on 10,427.

For a firm, the exposed group is not the junior bench. It is the senior tax associate or counsel who has passed the median without a decision and is still waiting past the point where most of the market has been promoted. Those lawyers know the market has already promoted most of their peers, and they are the ones a competitor can offer a title to.

The tail lines up with the work tax shares with private client. In the Sartori & Partners lateral database, 30.0% of tax lateral movers also practice private client and estates work, and 64.4% of private client movers also practice tax. Private client is one of the slowest tracks measured: 66.2% of its partners were promoted within 12 years, the average promotion came after 12.1 years, and its slowest quarter waited 14.0 years or more.

The transactional practices tax supports pull the other way. Corporate and M&A promoted 83.9% of its partners within 12 years and private equity 86.7%, with averages of 10.2 years and 9.8 years. Tax sits between the deal clock and the private wealth clock. A tax group that mostly serves deal teams can expect something close to the faster track; a group built around family offices, trusts and estate planning should plan for the private client pace, and say so to associates when they join.

A slow finish inside the firm meets a lateral market that can fill the seat now. Sartori & Partners data show 0.58 tax promotions for every lateral tax partner hired between June 2025 and May 2026, or 73.4% of the market rate of 0.79. Among practices of similar size, tax sits with the finance groups: banking and finance runs at 0.57 and funds at 0.58, while insurance runs at 0.82 and construction at 0.68.

Private client again offers the contrast. Despite its longer track, it promotes 0.76 partners per lateral partner, close to the market, so a slow clock does not force a firm to buy. Tax firms choose to. Portable work is one explanation: a tax partner who brings planning relationships and controversy matters can be priced on day one, while a promotion case takes years to build. The result for the reader is simple. In tax, the lateral search is the main supply line for new partners, and the promotion round is the smaller one.

Who moves confirms the pattern. In the 12 months to October 2026, partners made up 37.9% of tax lateral moves, against 27.7% across all practices. Settled tax partner moves numbered 272 against 213 a year earlier, so the count rose 27.7%. The promoted-per-lateral ratio already sets the promotions against lateral partner hires of the same months, so the two windows are not mixed here.

The lateral route is also a way around the slow internal finish. 15.5% of tax lateral moves came with a higher title at the new firm, against 12.9% market-wide. Some of those are associates and counsel who stopped waiting and took a partner title elsewhere. Every one of them is a promotion candidate a firm trained and then lost to the lateral market, and a vacancy it may refill with another lateral hire.

Two cities stand out on both sides of the ledger. Chicago takes 5.2% of tax lateral moves, an index of 123 against the market share, and Boston takes 3.4%, an index of 131. Across all practices, Chicago promoted 84.8% of its partners within 12 years and Boston 78.7%.

New York, the largest tax city at 13.7% of moves, runs a slower all-practice clock than either, with 73.2% promoted within 12 years. The three are set only against each other, not against the market-wide figure, because each country starts the clock at its own point of qualification. City promotion figures cover every practice, not tax alone, so they describe the local partnership culture a tax group sits in. Still, a firm with tax capacity in Chicago or Boston has a better chance of growing tax partners from inside than one relying on New York.

Manage the back of the track, not the front. Tax associates keep up with the market until the median, then the share through within 12 years falls 3.0 points below the market. Give senior tax associates a clear decision date before they reach 13.0 years, the point the slowest quarter of tax partners waits to.

Budget for buying. At 0.58 promotions per lateral partner, the promotion round alone will not grow a tax group. Plan lateral searches as the main source of new tax partners and set the internal track as the second, smaller source.

Match the track to the work. A tax bench tied to deal teams can promise something near the corporate pace; a bench tied to private client should promise the private client pace, where the average promotion comes after 12.1 years. Sartori & Partners data show that tax lawyers who outrun their firm's clock move laterally and come back as someone else's partner.