diff --git a/module/zfs/dmu_send.c b/module/zfs/dmu_send.c
index 8ecb99d5f57..4c354722e4f 100644
--- a/module/zfs/dmu_send.c
+++ b/module/zfs/dmu_send.c
@@ -1844,7 +1844,7 @@ send_reader_thread(void *arg)
 				continue;
 			}
 			uint64_t file_max =
-			    MIN(dn->dn_maxblkid, range->end_blkid);
+			    MIN(dn->dn_maxblkid + 1, range->end_blkid);
 			/*
 			 * The object exists, so we need to try to find the
 			 * blkptr for each block in the range we're processing.
diff --git a/tests/runfiles/common.run b/tests/runfiles/common.run
index 233fffee544..4c7e4e85ec0 100644
--- a/tests/runfiles/common.run
+++ b/tests/runfiles/common.run
@@ -906,7 +906,8 @@ tags = ['functional', 'quota']
 [tests/functional/redacted_send]
 tests = ['redacted_compressed', 'redacted_contents', 'redacted_deleted',
     'redacted_disabled_feature', 'redacted_embedded', 'redacted_holes',
-    'redacted_incrementals', 'redacted_largeblocks', 'redacted_many_clones',
+    'redacted_incrementals', 'redacted_largeblocks', 'redacted_max_blkid',
+    'redacted_many_clones',
     'redacted_mixed_recsize', 'redacted_mounts', 'redacted_negative',
     'redacted_origin', 'redacted_panic', 'redacted_props', 'redacted_resume',
     'redacted_size', 'redacted_volume']
diff --git a/tests/zfs-tests/tests/Makefile.am b/tests/zfs-tests/tests/Makefile.am
index 0c660f5feb8..c4bcfea5595 100644
--- a/tests/zfs-tests/tests/Makefile.am
+++ b/tests/zfs-tests/tests/Makefile.am
@@ -1899,6 +1899,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/redacted_send/redacted_holes.ksh \
 	functional/redacted_send/redacted_incrementals.ksh \
 	functional/redacted_send/redacted_largeblocks.ksh \
+	functional/redacted_send/redacted_max_blkid.ksh \
 	functional/redacted_send/redacted_many_clones.ksh \
 	functional/redacted_send/redacted_mixed_recsize.ksh \
 	functional/redacted_send/redacted_mounts.ksh \
diff --git a/tests/zfs-tests/tests/functional/redacted_send/redacted_max_blkid.ksh b/tests/zfs-tests/tests/functional/redacted_send/redacted_max_blkid.ksh
new file mode 100755
index 00000000000..13820b47022
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/redacted_send/redacted_max_blkid.ksh
@@ -0,0 +1,118 @@
+#!/bin/ksh
+# SPDX-License-Identifier: CDDL-1.0
+
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2026 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/tests/functional/redacted_send/redacted.kshlib
+
+#
+# Description:
+# Verify that an incremental send from a redaction bookmark correctly sends
+# the last block (dn_maxblkid) of a file through the PREVIOUSLY_REDACTED
+# path.
+#
+# Regression test for an off-by-one bug in the PREVIOUSLY_REDACTED handler
+# in send_reader_thread().  file_max was computed as:
+#
+#   MIN(dn->dn_maxblkid, range->end_blkid)
+#
+# dn_maxblkid is an inclusive maximum block ID while range->end_blkid is
+# exclusive (one past the last block).  Mixing these in MIN() caused the
+# loop condition "blkid < file_max" to skip block dn_maxblkid, silently
+# dropping the last block of any file whose last block was in the redaction
+# list.  The block remained as zeros on the receiver even though ZFS
+# reported the send and receive as successful.
+#
+# Strategy:
+# 1. Create a dataset with a 16-block file of random data and snapshot it.
+# 2. Create a clone (redact_clone) that overwrites only the last block
+#    (block 15, i.e., dn_maxblkid).
+# 3. Redact the base snapshot using redact_clone; block 15 enters the
+#    redaction list.
+# 4. Create a second clone (send_clone) of the base snapshot that does NOT
+#    modify block 15.  Because block 15 in send_clone has birth <=
+#    snap.creation_txg the TO traversal thread skips it; it must be sent
+#    via the PREVIOUSLY_REDACTED path.
+# 5. Redacted-send the base snapshot to the receiver (block 15 = zeros).
+# 6. Incrementally send send_clone from the redaction bookmark; block 15
+#    must be filled in by the PREVIOUSLY_REDACTED handler.
+# 7. Verify that block 15 on the receiver matches the original.
+#
+
+typeset ds_name="max_blkid"
+typeset sendfs="$POOL/$ds_name"
+typeset redact_clone="$POOL/${ds_name}_redact"
+typeset send_clone="$POOL/${ds_name}_send"
+typeset recvfs="$POOL2/$ds_name"
+typeset recv_clone="$POOL2/${ds_name}_send"
+typeset tmpdir="$(get_prop mountpoint $POOL)/tmp"
+typeset stream=$(mktemp $tmpdir/stream.XXXX)
+
+log_onexit redacted_cleanup $sendfs $recvfs $recv_clone
+
+# Create a dataset with a 16-block file.
+log_must zfs create $sendfs
+typeset mntpnt=$(get_prop mountpoint $sendfs)
+typeset bs=$(get_prop recsize $sendfs)
+log_must dd if=/dev/urandom of=$mntpnt/f1 bs=$bs count=16
+
+# Take the base snapshot.
+log_must zfs snapshot $sendfs@snap
+
+# Create redact_clone and overwrite ONLY the last block (block 15).
+# This is the block at index dn_maxblkid for a 16-block file.
+log_must zfs clone $sendfs@snap $redact_clone
+typeset redact_mnt=$(get_prop mountpoint $redact_clone)
+log_must dd if=/dev/urandom of=$redact_mnt/f1 bs=$bs count=1 seek=15 conv=notrunc
+log_must zfs snapshot $redact_clone@snap
+
+# Create the redaction bookmark; block 15 is now in the redaction list.
+log_must zfs redact $sendfs@snap book1 $redact_clone@snap
+
+# Create send_clone as an unmodified clone of the base snapshot.
+# Block 15 in send_clone is inherited (birth <= snap.creation_txg), so the
+# TO traversal thread does not include it.  The PREVIOUSLY_REDACTED path
+# must send it.
+log_must zfs clone $sendfs@snap $send_clone
+log_must zfs snapshot $send_clone@snap
+
+# Redacted send of the base snapshot; block 15 of f1 is omitted.
+log_must eval "zfs send --redact book1 $sendfs@snap >$stream"
+log_must eval "zfs recv $recvfs <$stream"
+
+# Incremental send of send_clone from the redaction bookmark.
+# Block 15 must be sent via the PREVIOUSLY_REDACTED path.
+log_must eval "zfs send -i $sendfs#book1 $send_clone@snap >$stream"
+log_must eval "zfs recv $recv_clone <$stream"
+
+# Verify that the received clone is identical to the source.
+# If the bug is present, block 15 is zeros on the receiver and this fails.
+typeset send_mnt=$(get_prop mountpoint $send_clone)
+typeset recv_mnt=$(get_prop mountpoint $recv_clone)
+log_must directory_diff $send_mnt $recv_mnt
+
+# Explicitly verify block 15 is not all zeros and matches the source.
+typeset src_block=$(mktemp $tmpdir/src_block.XXXX)
+typeset recv_block=$(mktemp $tmpdir/recv_block.XXXX)
+typeset zero_block=$(mktemp $tmpdir/zero_block.XXXX)
+log_must dd if=$mntpnt/f1 bs=$bs skip=15 count=1 of=$src_block 2>/dev/null
+log_must dd if=$recv_mnt/f1 bs=$bs skip=15 count=1 of=$recv_block 2>/dev/null
+log_must dd if=/dev/zero bs=$bs count=1 of=$zero_block 2>/dev/null
+
+cmp -s $recv_block $zero_block && log_fail "Block 15 is all zeros on receiver (off-by-one bug)"
+log_must cmp $src_block $recv_block
+
+log_pass "Incremental send from bookmark correctly sends the last block (dn_maxblkid)."