diff --git a/NAMESPACE b/NAMESPACE
index 987fcd2..0038066 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -106,6 +106,7 @@ export(loadAdatsAsList)
 export(locateSeqId)
 export(matchSeqIds)
 export(meltExpressionSet)
+export(merge_clin)
 export(mutate)
 export(parseHeader)
 export(pivotExpressionSet)
@@ -172,6 +173,7 @@ importFrom(tidyr,unite)
 importFrom(tools,md5sum)
 importFrom(utils,capture.output)
 importFrom(utils,head)
+importFrom(utils,read.csv)
 importFrom(utils,read.delim)
 importFrom(utils,tail)
 importFrom(utils,write.table)
diff --git a/R/merge-clin.R b/R/merge-clin.R
new file mode 100644
index 0000000..cf0dcd7
--- /dev/null
+++ b/R/merge-clin.R
@@ -0,0 +1,84 @@
+#' Merge Clinical Data into Data Frame
+#'
+#' Occasionally, additional clinical data is obtained _after_ samples
+#' have been submitted to SomaLogic, Inc. or even after 'SomaScan'
+#' results have been delivered.
+#' This requires the new clinical variables, i.e. non-proteomic, data to be
+#' merged with 'SomaScan' data into a "new" ADAT prior to analysis.
+#' This wrapper easily merges such clinical variables into an
+#' existing 2 dimensional data frame object, e.g. a `soma_adat`,
+#' and is a simple wrapper around [dplyr::left_join()].
+#'
+#' This is a package export of the `merge_clin.R` command-line tool (R script)
+#' that lives in the `cli/merge` system file directory. Please see:
+#' \itemize{
+#'   \item `dir(system.file("cli/merge", package = "SomaDataIO"), full.names = TRUE)`
+#'   \item `vignette("clin-merge-tool", package = "SomaDataIO")`
+#' }
+#'
+#' @inheritParams params
+#' @param clin_data One of 2 options:
+#' \itemize{
+#'   \item A data frame containing clinical variables to merge into `x`, or
+#'   \item A path to a file, typically a `*.csv`,
+#'     containing clinical variables to merge into `x`.
+#' }
+#' @param by A character vector of variables to join by.
+#'   See [dplyr::left_join()] for more details.
+#' @param ... Additional parameters passed to [dplyr::left_join()].
+#' @return An object of the same class as `x` with new clinical
+#'   variables merged.
+#' @author Stu Field
+#' @seealso [dplyr::left_join()]
+#' @examples
+#' # retrieve clinical data
+#' clin_file <- system.file("cli/merge/meta.csv", package = "SomaDataIO", mustWork = TRUE)
+#' clin_file
+#'
+#' # view clinical data to be merged:
+#' # 1) `group`
+#' # 2) `newvar`
+#' clin_df <- read.csv(clin_file, header = TRUE)
+#' clin_df
+#'
+#' # ensure compatible type for `by =`
+#' clin_df$SampleId <- as.character(clin_df$SampleId)
+#'
+#' # create mini-adat
+#' apts <- withr::with_seed(123, sample(getAnalytes(example_data), 3L))
+#' adat <- head(example_data, 10L) |>
+#'   dplyr::select(SampleId, all_of(apts))
+#'
+#' # merge clinical variables
+#' adat_merged <- merge_clin(adat, clin_df, by = "SampleId")
+#' adat_merged
+#'
+#' # Alternative syntax:
+#' #   merge on different variable names
+#' clin_df2 <- system.file("cli/merge/meta2.csv", package = "SomaDataIO",
+#'                         mustWork = TRUE) |> read.csv(header = TRUE)
+#' clin_df2
+#'
+#' clin_df2$ClinKey <- as.character(clin_df2$ClinKey)
+#' adat_merged2 <- merge_clin(adat, clin_df2, by = c(SampleId = "ClinKey"))
+#' adat_merged2
+#' @importFrom utils read.csv
+#' @importFrom dplyr left_join
+#' @export
+merge_clin <- function(x, clin_data, by = NULL, ...) {
+
+  stopifnot("`adat` must be a `soma_adat`."  = is.soma_adat(x))
+
+  if ( inherits(clin_data, "data.frame") ) {
+    clin_df <- clin_data
+  } else if ( is.character(clin_data) && length(clin_data) == 1L &&
+              file.exists(clin_data) ) {
+    clin_df <- normalizePath(clin_data, mustWork = TRUE) |>
+      utils::read.csv(header = TRUE)
+  } else {
+    stop("Invalid `clin` argument: ", .value(class(clin_data)), call. = FALSE)
+  }
+
+  dplyr::left_join(x, clin_df, by = by)
+}
+
diff --git a/_pkgdown.yml b/_pkgdown.yml
index d82b4aa..acdd335 100644
--- a/_pkgdown.yml
+++ b/_pkgdown.yml
@@ -136,6 +136,7 @@ reference:
     - starts_with("getAnalyte")
     - getMeta
     - diffAdats
+    - merge_clin
 
   - title: Transform Between SomaScan Versions
     desc: >
diff --git a/man/merge_clin.Rd b/man/merge_clin.Rd
new file mode 100644
index 0000000..c801261
--- /dev/null
+++ b/man/merge_clin.Rd
@@ -0,0 +1,84 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/merge-clin.R
+\name{merge_clin}
+\alias{merge_clin}
+\title{Merge Clinical Data into Data Frame}
+\usage{
+merge_clin(x, clin_data, by = NULL, ...)
+}
+\arguments{
+\item{x}{A \code{soma_adat} object (with intact attributes),
+typically created using \code{\link[=read_adat]{read_adat()}}.}
+
+\item{clin_data}{One of 2 options:
+\itemize{
+\item A data frame containing clinical variables to merge into \code{x}, or
+\item A path to a file, typically a \verb{*.csv},
+containing clinical variables to merge into \code{x}.
+}}
+
+\item{by}{A character vector of variables to join by.
+See \code{\link[dplyr:mutate-joins]{dplyr::left_join()}} for more details.}
+
+\item{...}{Additional parameters passed to \code{\link[dplyr:mutate-joins]{dplyr::left_join()}}.}
+}
+\value{
+An object of the same class as \code{x} with new clinical
+variables merged.
+}
+\description{
+It is very common that additional clinical variables were either
+not delivered with SomaScan data or they were collected \emph{after}
+the samples were collected, and thus need to be merged/joined
+with existing SomaScan data prior to analysis.
+This wrapper easily merges such clinical variables into an
+existing 2 dimensional data frame object, e.g. a \code{soma_adat},
+and is a simple wrapper around \code{\link[dplyr:mutate-joins]{dplyr::left_join()}}.
+}
+\details{
+This is an package export of the \code{merge_clin.R} command-line R script
+that lives in the \code{cli/merge} system file directory. Please see:
+\itemize{
+\item \code{dir(system.file("cli/merge", package = "SomaDataIO"), full.names = TRUE)}
+\item \code{vignette("clin-merge-tool", package = "SomaDataIO")}
+}
+}
+\examples{
+# retrieve clinical data
+clin_file <- system.file("cli/merge/meta.csv", package = "SomaDataIO", mustWork = TRUE)
+clin_file
+
+# view clinical data to be merged:
+# 1) `group`
+# 2) `newvar`
+clin_df <- read.csv(clin_file, header = TRUE)
+clin_df
+
+# ensure compatible type for `by =`
+clin_df$SampleId <- as.character(clin_df$SampleId)
+
+# create mini-adat
+apts <- withr::with_seed(123, sample(getAnalytes(example_data), 3L))
+adat <- head(example_data, 10L) |>
+  dplyr::select(SampleId, all_of(apts))
+
+# merge clinical variables
+adat_merged <- merge_clin(adat, clin_df, by = "SampleId")
+adat_merged
+
+# Alternative syntax:
+#   merge on different variable names
+clin_df2 <- system.file("cli/merge/meta2.csv", package = "SomaDataIO",
+                        mustWork = TRUE) |> read.csv(header = TRUE)
+clin_df2
+
+clin_df2$ClinKey <- as.character(clin_df2$ClinKey)
+adat_merged2 <- merge_clin(adat, clin_df2, by = c(SampleId = "ClinKey"))
+adat_merged2
+}
+\seealso{
+\code{\link[dplyr:mutate-joins]{dplyr::left_join()}}
+}
+\author{
+Stu Field
+}
diff --git a/vignettes/cli-merge-tool.Rmd b/vignettes/cli-merge-tool.Rmd
index 13bac86..c946eba 100644
--- a/vignettes/cli-merge-tool.Rmd
+++ b/vignettes/cli-merge-tool.Rmd
@@ -39,6 +39,9 @@ in the `cli/merge/` directory, which allows one to
 generate an updated `*.adat` file via the command-line without
 having to launch an integrated development environment ("IDE"), e.g. `RStudio`.
 
+To use `SomaDataIO`s exported functionality fro _within_ and R session,
+please see `merge_clin()`.
+
 
 ----------------