  As measurements of the neutrino oscillation parameters improve it is becoming
more interesting to study antineutrino oscillations, to investigate CP and CPT
violation in the lepton sector and nonstandard matter effects. We present the
most recent T2K antineutrino oscillation results, from data collected using a
muon antineutrino-enhanced neutrino beam corresponding to 4.01E20 protons on
target. The first analysis of electron antineutrino appearance at T2K is
presented, as well as world-leading measurements of the dominant oscillation
parameters for muon antineutrino disappearance. T2K measures
$\sin^2(\bar{\theta}_{23}) = 0.46^{+0.14}_{-0.06}$ and $\Delta \bar{m}^2_{32} =
2.50^{+0.3}_{-0.2} \times 10^{-3} \mbox{eV}^2$, which is consistent with
previous T2K measurements of the neutrino oscillation parameters and existing
antineutrino measurements.
