diff --git a/features.txt b/features.txt
index 3aa05db1f5b..83fc64f3d21 100644
--- a/features.txt
+++ b/features.txt
@@ -23,6 +23,10 @@ Intl.Locale-info
 # https://github.com/tc39/proposal-intl-numberformat-v3
 Intl.NumberFormat-v3
 
+# Keep trailing zeros in Intl.NumberFormat and Intl.PluralRules
+# https://github.com/tc39/proposal-intl-keep-trailing-zeros
+keep-trailing-zeros
+
 # Legacy RegExp features
 # https://github.com/tc39/proposal-regexp-legacy-features
 legacy-regexp
diff --git a/test/intl402/NumberFormat/prototype/format/value-decimal-string-trailing-zeros.js b/test/intl402/NumberFormat/prototype/format/value-decimal-string-trailing-zeros.js
new file mode 100644
index 00000000000..284e32522c4
--- /dev/null
+++ b/test/intl402/NumberFormat/prototype/format/value-decimal-string-trailing-zeros.js
@@ -0,0 +1,113 @@
+// Copyright (C) 2025 Mozilla Foundation. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: pending
+description: >
+  Intl.NumberFormat.prototype.format converts its argument (called value) to a
+  number using ToIntlMathematicalValue, and retains trailing zeros during formatting.
+features: [Intl.NumberFormat-v3, keep-trailing-zeros]
+locale: [en-US]
+---*/
+
+const nf = new Intl.NumberFormat('en-US', { maximumFractionDigits: 20 });
+
+assert.sameValue(nf.format('0'), '0');
+assert.sameValue(nf.format('1'), '1');
+assert.sameValue(nf.format('0.0'), '0.0');
+assert.sameValue(nf.format('1.0'), '1.0');
+assert.sameValue(nf.format('10.0'), '10.0');
+assert.sameValue(nf.format('0.10'), '0.10');
+assert.sameValue(nf.format('0.010'), '0.010');
+assert.sameValue(nf.format('.10'), '0.10');
+assert.sameValue(nf.format('.0'), '0.0');
+assert.sameValue(nf.format('00.0'), '0.0');
+assert.sameValue(nf.format('001'), '1');
+assert.sameValue(nf.format('-0.00'), '-0.00');
+assert.sameValue(nf.format('-.00'), '-0.00');
+assert.sameValue(nf.format('3.100'), '3.100');
+assert.sameValue(nf.format('6.000000'), '6.000000');
+assert.sameValue(nf.format('1.230e1'), '12.30');
+assert.sameValue(nf.format('1.230e0'), '1.230');
+assert.sameValue(nf.format('1.230e-1'), '0.1230');
+assert.sameValue(nf.format('1.230e-2'), '0.01230');
+assert.sameValue(nf.format('12.30e-1'), '1.230');
+assert.sameValue(nf.format('12.30e-2'), '0.1230');
+assert.sameValue(nf.format('12.30e-3'), '0.01230');
+assert.sameValue(nf.format('1.2345e-21'), '0.00000000000000000000');
+assert.sameValue(nf.format('1.2345e-100'), '0.00000000000000000000');
+assert.sameValue(nf.format('1.2345e-1000'), '0.00000000000000000000');
+
+// maximumFractionDigits defaults to 3
+const nf2 = new Intl.NumberFormat('en-US', { minimumFractionDigits: 1 });
+
+assert.sameValue(nf2.format('1'), '1.0');
+assert.sameValue(nf2.format('1.00'), '1.00');
+assert.sameValue(nf2.format('1.000000'), '1.000');
+assert.sameValue(nf2.format('0.999'), '0.999');
+assert.sameValue(nf2.format('0.9999'), '1.000');
+
+const nf3 = new Intl.NumberFormat('en-US', {
+  minimumSignificantDigits: 2,
+  maximumSignificantDigits: 4,
+});
+
+assert.sameValue(nf3.format('1'), '1.0');
+assert.sameValue(nf3.format('1.0'), '1.0');
+assert.sameValue(nf3.format('1.00'), '1.00');
+assert.sameValue(nf3.format('0.00'), '0.00');
+assert.sameValue(nf3.format('.00'), '0.00');
+assert.sameValue(nf3.format('0.000000'), '0.000');
+assert.sameValue(nf3.format('1.000000'), '1.000');
+assert.sameValue(nf3.format('1.99999'), '2.000');
+assert.sameValue(nf3.format('1.2'), '1.2');
+assert.sameValue(nf3.format('0.12'), '0.12');
+assert.sameValue(nf3.format('0.012'), '0.012');
+assert.sameValue(nf3.format('1.2345e-21'), '0.000000000000000000001235');
+assert.sameValue(nf3.format('1.2345e-1000'), '0.000');
+
+const nf4 = new NumberFormat('en-US', {
+  minimumSignificantDigits: 2,
+  maximumSignificantDigits: 4,
+  trailingZeroDisplay: 'stripToMinimum',
+});
+
+assert.sameValue(nf4.format('1'), '1.0');
+assert.sameValue(nf4.format('1.0'), '1.0');
+assert.sameValue(nf4.format('1.00'), '1.0');
+assert.sameValue(nf4.format('0.00'), '0.0');
+assert.sameValue(nf4.format('.00'), '0.0');
+assert.sameValue(nf4.format('0.000000'), '0.0');
+assert.sameValue(nf4.format('1.000000'), '1.0');
+assert.sameValue(nf4.format('1.99999'), '2.0');
+
+const pf = new Intl.NumberFormat('en-US', {
+  style: 'percent',
+  maximumFractionDigits: 10,
+});
+
+assert.sameValue(pf.format('1.0'), '100%');
+assert.sameValue(pf.format('1.00'), '100%');
+assert.sameValue(pf.format('0.50'), '50%');
+assert.sameValue(pf.format('0.5000'), '50.00%');
+
+const sf = new Intl.NumberFormat('en-US', { notation: 'scientific' });
+
+assert.sameValue(sf.format('0.1'), '1E-1');
+assert.sameValue(sf.format('0.01'), '1E-2');
+assert.sameValue(sf.format('0.01200'), '1.200E-2');
+assert.sameValue(sf.format('120.0'), '1.200E2');
+assert.sameValue(sf.format('12.00e-3'), '1.200E-2');
+assert.sameValue(sf.format('1.200e-3'), '1.200E-3');
+assert.sameValue(sf.format('.1200e-3'), '1.200E-4');
+
+const spf = new Intl.NumberFormat('en-US', {
+  style: 'percent',
+  notation: 'scientific',
+  maximumFractionDigits: 10,
+});
+
+assert.sameValue(spf.format('0.0'), '0.0E0%');
+assert.sameValue(spf.format('1.0'), '1.0E2%');
+assert.sameValue(spf.format('1.00'), '1.00E2%');
+assert.sameValue(spf.format('0.50'), '5.0E1%');
+assert.sameValue(spf.format('0.5000'), '5.000E1%');