diff --git a/titan/features/partner_tracing.py b/titan/features/partner_tracing.py
index 36251c68..c1149963 100644
--- a/titan/features/partner_tracing.py
+++ b/titan/features/partner_tracing.py
@@ -68,12 +68,12 @@ def update_agent(self, model: "model.TITAN"):
         
         # Starting Jan 2021, use improved PS parameters
         if model.time >= 48:
-            params.participate_prob[self.agent.race] = params.participate_prob_improved[self.agent.race]
+            params[self.agent.race].participate_prob = params[self.agent.race].participate_prob_improved
             params.tracing_prob = params.tracing_prob_improved
-            params.contact_prob[self.agent.race] = params.contact_prob_improved[self.agent.race]
-            params.partner_participate_prob[self.agent.race] = params.partner_participate_prob_improved[self.agent.race]
+            params[self.agent.race].contact_prob = params[self.agent.race].contact_prob_improved
+            params[self.agent.race].partner_participate_prob = params[self.agent.race].partner_participate_prob_improved
             params.treatment_prob = params.treatment_prob_improved
-            params.prep_prob[self.agent.race] = params.prep_prob_improved[self.agent.race]
+            params[self.agent.race].prep_prob = params[self.agent.race].prep_prob_improved
             params.re_haart_prob = params.re_haart_prob_improved
             
         if model.time < params.start_time or model.time > params.stop_time:
@@ -85,7 +85,7 @@ def update_agent(self, model: "model.TITAN"):
             and agent_exposure.dx_time == model.time - 1
         ):  
             # step 1 
-            self.participate = True if model.run_random.random() < params.participate_prob[self.agent.race] else False
+            self.participate = True if model.run_random.random() < params[self.agent.race].participate_prob else False
 
             if self.participate:
                 self.participate_time = model.time
@@ -97,7 +97,7 @@ def update_agent(self, model: "model.TITAN"):
         if (
             self.active
             and self.time < model.time
-            and model.run_random.random() < params.partner_participate_prob[self.agent.race]
+            and model.run_random.random() < params[self.agent.race].partner_participate_prob
         ):  
             # mark agents who participate
             self.ps_participant = True
@@ -159,7 +159,7 @@ def trace_partners(self, params, model: "model.TITAN"):
             # step 3
             self.info = True if model.run_random.random() < params.tracing_prob else False # can only trace if participant provides information
             # step 4
-            self.contact = True if model.run_random.random() < params.contact_prob[ptnr.race] else False # contact stochastically
+            self.contact = True if model.run_random.random() < params[ptnr.race].contact_prob else False # contact stochastically
             
             if self.info:
                 self.info_stat += 1
diff --git a/titan/features/prep.py b/titan/features/prep.py
index b1c4241e..3c806ee8 100644
--- a/titan/features/prep.py
+++ b/titan/features/prep.py
@@ -194,7 +194,7 @@ def initiate(self, model: "model.TITAN", force: bool = False):
                         
             # else if agent tested negative through PS, use appropriate probability
             elif "Racial" in params.prep.target_model and self.agent.partner_tracing.tested_negative:
-                prep_prob = self.agent.location.params.partner_tracing.prep_prob[self.agent.race]
+                prep_prob = self.agent.location.params.partner_tracing[self.agent.race].prep_prob
                 if model.run_random.random() <= prep_prob:
                     self.enroll(model.run_random, model.time)
                     self.ps_prep = True
@@ -202,7 +202,7 @@ def initiate(self, model: "model.TITAN", force: bool = False):
                     
             else:
                 if self.agent.partner_tracing.tested_negative:
-                    prep_prob = self.agent.location.params.partner_tracing.prep_prob[self.agent.race]
+                    prep_prob = self.agent.location.params.partner_tracing[self.agent.race].prep_prob
                     if model.run_random.random() <= prep_prob:
                         self.enroll(model.run_random, model.time)
                         self.ps_prep = True
@@ -232,7 +232,7 @@ def initiate(self, model: "model.TITAN", force: bool = False):
                     
             # tested through PS
             elif self.agent.partner_tracing.tested_negative:
-                target_prep = self.agent.partner_tracing.get_negative_count() * self.agent.location.params.partner_tracing.prep_prob[self.agent.race]
+                target_prep = self.agent.partner_tracing.get_negative_count() * self.agent.location.params.partner_tracing[self.agent.race].prep_prob
                 
                 if self.ps_get_stat() < target_prep:
                     self.enroll(model.run_random, model.time)
diff --git a/titan/params/partner_tracing.yml b/titan/params/partner_tracing.yml
index 1bc74778..71a18476 100644
--- a/titan/params/partner_tracing.yml
+++ b/titan/params/partner_tracing.yml
@@ -37,108 +37,192 @@ partner_tracing:
       description: "For how many time steps after partner diagnosis a partner is traced"
       type: int
       default: 1
-    participate_prob:
-      description: Probability that a given agent is willing to participate in the partner services program
-      type: float
-      default: 
-        white: 0.630
-        black: 0.561
-        latino: 0.580
-      min: 0
-      max: 1
+      
+    white:
+      participate_prob:
+        description: Probability that a given agent is willing to participate in the partner services program
+        type: float
+        default: 0.630
+        min: 0
+        max: 1
+      contact_prob:
+        description: Probability that a named partner will be contacted
+        type: float
+        default: 0.7
+        min: 0  
+        max: 1
+      partner_participate_prob:
+        description: Probability that a contacted partner will participate in the PS and get tested
+        type: float
+        default: 0.56
+        min: 0
+        max: 1
+      prep_prob:
+        description: Probability that a partner who tested negative for HIV through PS will be referred to prep
+        type: float
+        default: 0.49
+        min: 0
+        max: 1    
+      participate_prob_improved:
+        description: Probability that a given agent is willing to participate in the partner services program
+        type: float
+        default: 0.630
+        min: 0
+        max: 1
+      contact_prob_improved:
+        description: Probability that a named partner will be contacted
+        type: float
+        default: 0.7
+        min: 0  
+        max: 1
+      partner_participate_prob_improved:
+        description: Probability that a contacted partner will participate in the PS and get tested
+        type: float
+        default: 0.56
+        min: 0
+        max: 1
+      prep_prob_improved:
+        description: Probability that a partner who tested negative for HIV through PS will be referred to prep
+        type: float
+        default: 0.49
+        min: 0
+        max: 1  
+        
+    black:
+      participate_prob:
+        description: Probability that a given agent is willing to participate in the partner services program
+        type: float
+        default: 0.561
+        min: 0
+        max: 1
+      contact_prob:
+        description: Probability that a named partner will be contacted
+        type: float
+        default: 0.69
+        min: 0  
+        max: 1
+      partner_participate_prob:
+        description: Probability that a contacted partner will participate in the PS and get tested
+        type: float
+        default: 0.49
+        min: 0
+        max: 1
+      prep_prob:
+        description: Probability that a partner who tested negative for HIV through PS will be referred to prep
+        type: float
+        default: 0.5
+        min: 0
+        max: 1 
+      participate_prob_improved:
+        description: Probability that a given agent is willing to participate in the partner services program
+        type: float
+        default: 0.561
+        min: 0
+        max: 1
+      contact_prob_improved:
+        description: Probability that a named partner will be contacted
+        type: float
+        default: 0.69
+        min: 0  
+        max: 1
+      partner_participate_prob_improved:
+        description: Probability that a contacted partner will participate in the PS and get tested
+        type: float
+        default: 0.49
+        min: 0
+        max: 1
+      prep_prob_improved:
+        description: Probability that a partner who tested negative for HIV through PS will be referred to prep
+        type: float
+        default: 0.5
+        min: 0
+        max: 1   
+        
+    latino:
+      participate_prob:
+        description: Probability that a given agent is willing to participate in the partner services program
+        type: float
+        default: 0.580
+        min: 0
+        max: 1
+      contact_prob:
+        description: Probability that a named partner will be contacted
+        type: float
+        default: 0.75
+        min: 0  
+        max: 1
+      partner_participate_prob:
+        description: Probability that a contacted partner will participate in the PS and get tested
+        type: float
+        default: 0.54
+        min: 0
+        max: 1
+      prep_prob:
+        description: Probability that a partner who tested negative for HIV through PS will be referred to prep
+        type: float
+        default: 0.4
+        min: 0
+        max: 1 
+      participate_prob_improved:
+        description: Probability that a given agent is willing to participate in the partner services program
+        type: float
+        default: 0.580
+        min: 0
+        max: 1
+      contact_prob_improved:
+        description: Probability that a named partner will be contacted
+        type: float
+        default: 0.75
+        min: 0  
+        max: 1
+      partner_participate_prob_improved:
+        description: Probability that a contacted partner will participate in the PS and get tested
+        type: float
+        default: 0.54
+        min: 0
+        max: 1
+      prep_prob_improved:
+        description: Probability that a partner who tested negative for HIV through PS will be referred to prep
+        type: float
+        default: 0.4
+        min: 0
+        max: 1   
+        
     tracing_prob: 
       description: Probability of tracing a partner based on the amount of information provided by agent
       type: float
       default: 0.66 # calibrated
       min: 0
       max: 1
-    contact_prob:
-      description: Probability that a named partner will be contacted
-      type: float
-      default:
-       white: 0.7
-       black: 0.69
-       latino: 0.75
-      min: 0  
-      max: 1
-    partner_participate_prob:
-      description: Probability that a contacted partner will participate in the PS and get tested
-      type: float
-      default:
-        white: 0.56
-        black: 0.49
-        latino: 0.54
-      min: 0
-      max: 1
+    
     treatment_prob:
       description: Probability that a partner who has been diagnosed through PS will receive treatment
       type: float
       default: 0.82
       min: 0
       max: 1
-    prep_prob:
-      description: Probability that a partner who tested negative for HIV through PS will be referred to prep
-      type: float
-      default:
-        white: 0.49
-        black: 0.5
-        latino: 0.4
-      min: 0
-      max: 1  
+
     re_haart_prob:
       description: Probability that a traced agent who has been previously diagnosed and not on haart reengages/engages haart
       type: float
       default: 0.549
       min: 0
       max: 1  
-    participate_prob_improved:
-      description: Probability that a given agent is willing to participate in the partner services program
-      type: float
-      default: 
-        white: 0.961
-        black: 0.855
-        latino: 0.884
-      min: 0
-      max: 1
+      
     tracing_prob_improved: 
       description: Probability of tracing a partner based on the amount of information provided by agent
       type: float
       default: 0.9 # calibrated
       min: 0
       max: 1
-    contact_prob_improved:
-      description: Probability that a named partner will be contacted
-      type: float
-      default:
-       white: 0.883
-       black: 0.871
-       latino: 0.946
-      min: 0  
-      max: 1
-    partner_participate_prob_improved:
-      description: Probability that a contacted partner will participate in the PS and get tested
-      type: float
-      default:
-        white: 0.951
-        black: 0.832
-        latino: 0.917
-      min: 0
-      max: 1
+
     treatment_prob_improved:
       description: Probability that a partner who has been diagnosed through PS will receive treatment
       type: float
       default: 0.9
       min: 0
       max: 1
-    prep_prob_improved:
-      description: Probability that a partner who tested negative for HIV through PS will be referred to prep
-      type: float
-      default:
-        white: 0.942
-        black: 0.972
-        latino: 0.786
-      min: 0
-      max: 1  
+
     re_haart_prob_improved:
       description: Probability that a traced agent who has been previously diagnosed and not on haart reengages/engages haart
       type: float