The practice of the Pilot Flying (PF) transferring aircraft control to the Pilot Not Flying (PNF) during landing rollout — typically after thrust reversers are stowed and the aircraft is decelerating through moderate groundspeed — is a procedural convention observed across numerous airline, Part 135, and business aviation operations. It is not mandated by 14 CFR regulations, and the FAA imposes no rule requiring or prohibiting mid-rollout control transfers. The behavior is almost entirely driven by operator Standard Operating Procedures (SOPs), crew agreements, and — as the original question correctly intuited — logbook currency considerations under 14 CFR §61.57.
The currency dimension is the most operationally significant driver. Under §61.57(a), a pilot must have performed at least three takeoffs and landings within the preceding 90 days to act as PIC carrying passengers, with additional night currency requirements layered on top. In high-frequency airline operations, both crewmembers may have adequate currency without deliberate management, but in low-utilization environments — fractional operations, on-demand charter, and corporate flight departments flying irregular schedules — landing currency can become a genuine planning concern. By transferring control during rollout, the PNF completes the ground deceleration and taxi-in, which some operators' SOPs credit as a loggable landing for that pilot. Whether this practice fully satisfies the regulatory definition of a "landing" under §61.1 and §61.51 is a subject of ongoing interpretive discussion among operators and FAA inspectors, and companies with Letter of Interpretation requests or published guidance from their POI have clearer standing than those relying on informal convention.
The taxi-out question is directly linked. In most structured two-pilot operations, the crew agrees on PF/PNF assignments for an entire leg — from pushback through engine shutdown — and those designations carry logbook implications for both takeoff and landing credit. When a crew intends to equitably distribute landings across a rotation or trip, it is common for the pilot who taxied in (having accepted control on rollout) to also handle the taxi out on that turn or the next departure, either as the designated PF for the outbound leg or simply to maintain continuity of ground handling duties. Operators with formal "leg trading" or "T&L equalization" policies will specify this explicitly in their OpSpecs or Flight Operations Manuals, removing ambiguity about who logs what.
Broader context matters here for professional pilots operating under Part 91K, 135, or 121. The FAA's stance on logging flight time and landings emphasizes that logbook entries must accurately reflect what the pilot actually did — manipulation of control transfers purely to manufacture currency entries without genuine pilot-in-command responsibility runs contrary to the spirit of §61.51 and has been a point of scrutiny during certificate actions. Operators with well-constructed SOPs that define control transfer points, specify which crewmember logs associated flight time, and tie those definitions to published training standards are in the strongest regulatory position. Pilots operating under less formalized arrangements — particularly in Part 91 corporate or owner-flown turbine operations — are well advised to ensure their logbook practices align with any applicable OpSpecs or, absent those, with AOPA and NBAA guidance on acceptable logging conventions for multi-crew aircraft.