Covariate Adjustment for Randomized Controlled Trials R package RCTCovAdj version 0.1.0 Implements covariate-adjusted estimation and inference for marginal mean differences in two-arm randomized controlled trials with continuous outcomes. Methods include the unadjusted difference in means, common-slope analysis of covariance, interacted standardization with joint influence-function inference, and cross-fitted augmentation. The package also provides analytic power and sample-size calculations, reproducible simulation designs, and article replication workflows, including tools for verifying and analyzing an authorized local trial-data file. The adjustment methods build on Tsiatis et al. (2008) <doi:10.1002/sim.3113> and Lin (2013) <doi:10.1214/12-AOAS583>. Software Depends: R (>= 4.1.0) Imports: digest, graphics, grDevices, parallel, stats, tools, utils Suggests: knitr, medicaldata (>= 0.2.0), rmarkdown, testthat (>= 3.0.0), withr Se Yoon Lee <seyoonlee.stat.math@gmail.com> Comprehensive R Archive Network (CRAN) Se Yoon Lee [aut, cre, cph] MIT + file LICENSE (https://CRAN.R-project.org/package=RCTCovAdj/LICENSE) 2026-09-24 application/tgz https://CRAN.R-project.org/package=RCTCovAdj doi:10.32614/CRAN.package.RCTCovAdj