diff --git a/fcl/detsim/detsim_2d_icarus_refactored_yzsim_Run4.fcl b/fcl/detsim/detsim_2d_icarus_refactored_yzsim_Run4.fcl
new file mode 100644
index 000000000..f2a5339a3
--- /dev/null
+++ b/fcl/detsim/detsim_2d_icarus_refactored_yzsim_Run4.fcl
@@ -0,0 +1,3 @@
+#include "detsim_2d_icarus_refactored_yzsim.fcl"
+
+physics.producers.daq.wcls_main.params.YZScaleMapJson: "yzmap_gain_icarus_v4_run4.json"
diff --git a/fcl/detsim/detsim_2d_icarus_refactored_yzsim_overlay_Run4.fcl b/fcl/detsim/detsim_2d_icarus_refactored_yzsim_overlay_Run4.fcl
new file mode 100644
index 000000000..92158743e
--- /dev/null
+++ b/fcl/detsim/detsim_2d_icarus_refactored_yzsim_overlay_Run4.fcl
@@ -0,0 +1,3 @@
+#include "detsim_2d_icarus_refactored_yzsim_overlay.fcl"
+
+physics.producers.daq.wcls_main.params.YZScaleMapJson: "yzmap_gain_icarus_v4_run4.json"
diff --git a/icaruscode/TPC/ICARUSWireCell/detsimmodules_wirecell_ICARUS.fcl b/icaruscode/TPC/ICARUSWireCell/detsimmodules_wirecell_ICARUS.fcl
index f01f766cc..8868eb3e1 100644
--- a/icaruscode/TPC/ICARUSWireCell/detsimmodules_wirecell_ICARUS.fcl
+++ b/icaruscode/TPC/ICARUSWireCell/detsimmodules_wirecell_ICARUS.fcl
@@ -2,6 +2,8 @@
 #include "services_basic_icarus.fcl"
 // We need this for diffusion
 #include "simulationservices_icarus.fcl"
+// lookup calibration tags
+#include "calibration_database_GlobalTags_icarus.fcl"
 
 BEGIN_PROLOG
 
@@ -35,6 +37,11 @@ icarus_simwire_wirecell:
 	    file_rcresp: "icarus_fnal_rc_tail.json" # use the RCResponse by default
 	    cathode_input_format: "array" # scalar (flat) or array (bent)
             SimEnergyDepositLabel: "ionization"
+            # yz map config -- default to Run 2
+            YZScaleMapJson: "yzmap_gain_icarus_v4_run2.json"
+            YZMapJson: "yzmap_icarus_v3_run2.json"
+            DBFileName: "tpc_elifetime_data"
+            DBTag: @local::ICARUS_Calibration_GlobalTags.tpc_elifetime_data
 	}
         structs: {
             # load values from simulationservices_icarus.fcl
diff --git a/icaruscode/TPC/ICARUSWireCell/icarus/sim.jsonnet b/icaruscode/TPC/ICARUSWireCell/icarus/sim.jsonnet
index e11d5c8d5..bd64391bf 100644
--- a/icaruscode/TPC/ICARUSWireCell/icarus/sim.jsonnet
+++ b/icaruscode/TPC/ICARUSWireCell/icarus/sim.jsonnet
@@ -111,8 +111,8 @@ function(params, tools) {
 		ar39activity: 0, // no simulated activity
 
 		// DB config
-		DBFileName: "tpc_elifetime_data",
-		DBTag: "v2r1",
+		DBFileName: std.extVar("DBFileName"),
+		DBTag: std.extVar("DBTag"),
 		ELifetimeCorrection: true,
 		Verbose: false,
 		TPC: 0,
diff --git a/icaruscode/TPC/ICARUSWireCell/icarus/wcls-multitpc-sim-drift-simchannel-yzsim-refactored.jsonnet b/icaruscode/TPC/ICARUSWireCell/icarus/wcls-multitpc-sim-drift-simchannel-yzsim-refactored.jsonnet
index 42b0e9eba..f2ed2310e 100644
--- a/icaruscode/TPC/ICARUSWireCell/icarus/wcls-multitpc-sim-drift-simchannel-yzsim-refactored.jsonnet
+++ b/icaruscode/TPC/ICARUSWireCell/icarus/wcls-multitpc-sim-drift-simchannel-yzsim-refactored.jsonnet
@@ -221,7 +221,7 @@ local scalers = [{
         type: "Scaler",
 	name: "scaler%d" %n, //%std.floor(n/45),
         data: params.lar {
-	        	 yzmap_scale_filename: 'yzmap_gain_icarus_v4_run2.json',
+	        	 yzmap_scale_filename: std.extVar('YZScaleMapJson'),
 			 bin_width:  10*wc.cm,
 			 tpc_width: 1500*wc.mm,
 			 bin_height: 10*wc.cm,
@@ -416,7 +416,7 @@ local deposetfilteryz = [ g.pnode({
             type: 'DepoSetFilterYZ',
    	    name: 'deposetfilteryz_resp%d-'%std.mod(r,15)+'plane%d-'%std.mod(std.floor(r/15),3)+tools.anodes[std.floor(r/45)].name,
             data: {
-	    	  yzmap_filename: 'yzmap_icarus_v3_run2.json',
+	    	  yzmap_filename: std.extVar('YZMapJson'),
 		  bin_width:  10*wc.cm,
 		  tpc_width: 1500*wc.mm,
 		  bin_height: 10*wc.cm,