We present a new measurement of the positive muon magnetic anomaly, aμ≡(gμ-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, ω˜p′, and of the anomalous precession frequency corrected for beam dynamics effects, ωa. From the ratio ωa/ω˜p′, together with precisely determined external parameters, we determine aμ=116 592 057(25)×10-11 (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain aμ(FNAL)=116 592 055(24)×10-11 (0.20 ppm). The new experimental world average is aμ(exp)=116 592 059(22)×10-11 (0.19 ppm), which represents a factor of 2 improvement in precision
