diff --git a/Indicators/Household-Dietary-Diversity-Score/HDDS.R b/Indicators/Household-Dietary-Diversity-Score/HDDS.R
new file mode 100644
index 0000000..3e19408
--- /dev/null
+++ b/Indicators/Household-Dietary-Diversity-Score/HDDS.R
@@ -0,0 +1,112 @@
+# ------------------------------------------------------------
+# WFP Standardized Scripts
+# Household Dietary Diversity Score (HDDS)
+# Last Updated: January 2026
+# ------------------------------------------------------------
+
+library(dplyr)
+
+# HDDS food groups (0/1 consumption in last 24h)
+hdds_vars <- c(
+  "HDDSStapCer","HDDSStapRoot","HDDSPulse","HDDSDairy",
+  "HDDSPrMeat","HDDSPrFish","HDDSPrEggs",
+  "HDDSVeg","HDDSFruit","HDDSFat","HDDSSugar","HDDSCond"
+)
+
+# ------------------------------------------------------------
+# 1) Check individual food groups
+# ------------------------------------------------------------
+hdds_stats_before <- df %>%
+  summarise(across(all_of(hdds_vars),
+                   list(min  = ~min(as.numeric(.x), na.rm = TRUE),
+                        max  = ~max(as.numeric(.x), na.rm = TRUE),
+                        mean = ~mean(as.numeric(.x), na.rm = TRUE))))
+hdds_stats_before
+
+# ------------------------------------------------------------
+# 2) Clean impossible values
+# ------------------------------------------------------------
+df <- df %>%
+  mutate(across(all_of(hdds_vars), ~ as.numeric(.x))) %>%
+  mutate(across(all_of(hdds_vars),
+                ~ ifelse(.x < 0 | .x >= 2, NA_real_, .x)))
+
+# ------------------------------------------------------------
+# 3) Compute HDDS
+# ------------------------------------------------------------
+df <- df %>%
+  mutate(
+    HDDS = HDDSStapCer + HDDSStapRoot + HDDSPulse + HDDSDairy +
+      HDDSPrMeat + HDDSPrFish + HDDSPrEggs +
+      HDDSVeg + HDDSFruit + HDDSFat + HDDSSugar + HDDSCond
+  )
+
+# ------------------------------------------------------------
+# 4) Clean impossible HDDS values
+#    Valid range: 0–12
+# ------------------------------------------------------------
+df <- df %>%
+  mutate(
+    HDDS = ifelse(HDDS < 0 | HDDS >= 13, NA_real_, HDDS)
+  )
+
+
+# ------------------------------------------------------------
+# 5) Data quality flags (HDDS internal + cross-check with FCS)
+# ------------------------------------------------------------
+df <- df %>%
+  mutate(
+    # Absolute HDDS checks
+    HDDS_flag_zero = ifelse(!is.na(HDDS) & HDDS == 0, 1L, 0L),
+    HDDS_flag_low  = ifelse(!is.na(HDDS) & HDDS <= 2, 1L, 0L),
+    HDDS_flag_high = ifelse(!is.na(HDDS) & HDDS >= 10, 1L, 0L),
+    
+    # Cross-checks against FCS module (7 days)
+    HDDS_flag_cereal  = ifelse(FCSStap  == 7 & HDDSStapCer == 0 & HDDSStapRoot == 0, 1L, 0L),
+    HDDS_flag_pulses  = ifelse(FCSPulse == 7 & HDDSPulse   == 0, 1L, 0L),
+    HDDS_flag_dairy   = ifelse(FCSDairy == 7 & HDDSDairy   == 0, 1L, 0L),
+    HDDS_flag_protein = ifelse(FCSPr == 7 &
+                                 HDDSPrMeat == 0 & HDDSPrEggs == 0 & HDDSPrFish == 0, 1L, 0L),
+    HDDS_flag_veg     = ifelse(FCSVeg   == 7 & HDDSVeg     == 0, 1L, 0L),
+    HDDS_flag_fruit   = ifelse(FCSFruit == 7 & HDDSFruit   == 0, 1L, 0L),
+    HDDS_flag_fat     = ifelse(FCSFat   == 7 & HDDSFat     == 0, 1L, 0L),
+    HDDS_flag_sugar   = ifelse(FCSSugar == 7 & HDDSSugar   == 0, 1L, 0L),
+    HDDS_flag_cond    = ifelse(FCSCond  == 7 & HDDSCond    == 0, 1L, 0L)
+  )
+
+# ------------------------------------------------------------
+# 6) Check flagged cases
+# ------------------------------------------------------------
+flag_vars <- c(
+  "HDDS_flag_zero","HDDS_flag_low","HDDS_flag_high",
+  "HDDS_flag_cereal","HDDS_flag_pulses","HDDS_flag_dairy",
+  "HDDS_flag_protein","HDDS_flag_veg","HDDS_flag_fruit",
+  "HDDS_flag_fat","HDDS_flag_sugar","HDDS_flag_cond"
+)
+
+lapply(flag_vars, function(v) table(df[[v]], useNA = "ifany"))
+
+# ------------------------------------------------------------
+# 7) Optional: IPC-oriented HDDS categories
+# ------------------------------------------------------------
+df <- df %>%
+  mutate(
+    HDDSCat_IPC = case_when(
+      is.na(HDDS) ~ NA_integer_,
+      HDDS <= 2   ~ 3L,
+      HDDS %in% c(3,4) ~ 2L,
+      HDDS >= 5   ~ 1L
+    ),
+    HDDSCat_IPC = factor(
+      HDDSCat_IPC,
+      levels = c(1,2,3),
+      labels = c(
+        "5–12 food groups (IPC phase 1–2)",
+        "3–4 food groups (IPC phase 3)",
+        "0–2 food groups (IPC phase 4–5)"
+      )
+    )
+  )
+
+table(df$HDDSCat_IPC, useNA = "ifany")
+