Unpivot Month Columns in Power Query M

Unpivots only the columns that look like month names, leaving key columns like ID or Region untouched.

Table TransformationsIntermediateunpivotmonthsreshape

Power Query M code

let
    Source = YourTable,
    MonthNames = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"},
    MonthColumns = List.Select(Table.ColumnNames(Source), each List.Contains(MonthNames, _)),
    Unpivoted = Table.UnpivotOtherColumns(Source, List.RemoveItems(Table.ColumnNames(Source), MonthColumns), "Month", "Value")
in
    Unpivoted

Notes

Adjust MonthNames to match how the month columns are labeled in your source (e.g. "January" or "2026-01").

Requirements

A table with one column per month and one or more identifier columns.

How to use this snippet

In Power BI Desktop, choose Transform data to open Power Query, then open the Advanced Editor on a query (or start from a blank query).
Paste the snippet and replace the placeholder names (tables, columns, file paths) with your own. Check the requirements above first.
Run it through the Power Query M Formatter to tidy the layout.

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