This talk will present a search for pair production of higgsinos in scenarios with gauge-mediated supersymmetry breaking. Each higgsino is assumed to decay into a Higgs boson and a nearly-massless gravitino. The search targets the bb decay channel of the Higgs bosons, leading to a reconstructed final state with at least three energetic b-jets and missing transverse momentum. Two complementary analysis channels are used to target higgsino masses below and above 250 GeV. The low (high) mass channel uses 126 (139) inverse femtobarns of sqrt(s)=13 TeV data collected by the ATLAS detector during Run 2 of the Large Hadron Collider, extending previous ATLAS results with 24.3 (36.1) inverse femtobarns. No significant excess above the Standard Model prediction is observed. At 95% confidence level, higgsino masses below 950 GeV are excluded. Exclusion limits as a function of the higgsino decay branching ratio to a Z or a Higgs boson are also presented.