Double Machine Learning with Instrumental Variables and Heterogeneity R package IVDML version 1.0.1 Instrumental variable (IV) estimators for homogeneous and heterogeneous treatment effects with efficient machine learning instruments. The estimators are based on double/debiased machine learning allowing for nonlinear and potentially high-dimensional control variables. Details can be found in Scheidegger, Guo and Bühlmann (2025) "Inference for heterogeneous treatment effects with efficient instruments and machine learning" <doi:10.48550/arXiv.2503.03530>. Software Imports: mgcv, ranger, stats, xgboost (>= 3.1.2.1) Suggests: testthat (>= 3.0.0) Cyrill Scheidegger <cyrill.scheidegger@stat.math.ethz.ch> Comprehensive R Archive Network (CRAN) Cyrill Scheidegger [aut, cre, cph] (ORCID: <https://orcid.org/0009-0005-2851-1384>) GPL (>= 3) 2025-12-12 application/tgz https://CRAN.R-project.org/package=IVDML doi:10.32614/CRAN.package.IVDML