diff --git a/cosmosis/output/cosmomc_output.py b/cosmosis/output/cosmomc_output.py
index b7d38806..a02bfd4d 100644
--- a/cosmosis/output/cosmomc_output.py
+++ b/cosmosis/output/cosmomc_output.py
@@ -9,7 +9,7 @@
 
 
 class CosmoMCOutput(TextColumnOutput):
-    def __init__(self, filename, rank=0, nchain=1, delimiter='    ', lock=True, resume=False):
+    def __init__(self, filename, rank=0, nchain=1, delimiter='    ', lock=True, resume=False, blinding_offset_file=None):
         super(CosmoMCOutput, self).__init__(filename, rank, nchain, '', lock=lock, resume=resume)
         if filename.endswith(self.FILE_EXTENSION):
             filename = filename[:-len(self.FILE_EXTENSION)]
@@ -19,6 +19,10 @@ def __init__(self, filename, rank=0, nchain=1, delimiter='    ', lock=True, resu
             self._paramfile = None
         self._last_params = None
         self._multiplicity = 0
+        if blinding_offset_file is not None:
+            self._blinding_offsets = np.load(blinding_offset_file)
+        else:
+            self._blinding_offsets = None
 
     def _close(self):
         self._write_parameters_multiplicity()
@@ -97,5 +101,6 @@ def load_from_options(cls, options):
     def from_options(cls, options, resume=False):
         if resume:
             raise ValueError("Cannot resume from cosmomc files yet")
-        return super(CosmoMCOutput,cls).from_options(options, resume=False)
+        blinding_offset_file = options.get('blinding_offsets', None)
+        return super(CosmoMCOutput,cls).from_options(options, resume=False, blinding_offset_file=blinding_offset_file)
 
diff --git a/cosmosis/output/fits_output.py b/cosmosis/output/fits_output.py
index 2b178eea..abf33055 100644
--- a/cosmosis/output/fits_output.py
+++ b/cosmosis/output/fits_output.py
@@ -33,7 +33,7 @@ class FitsOutput(OutputBase):
     FILE_EXTENSION = ".fits"
     _aliases = ["fits"]
 
-    def __init__(self, filename, rank=0, nchain=1, clobber=True):
+    def __init__(self, filename, rank=0, nchain=1, clobber=True, blinding_offset_file=None):
         super(FitsOutput, self).__init__()
 
         #If filename already ends in .txt then remove it for a moment
@@ -56,6 +56,11 @@ def __init__(self, filename, rank=0, nchain=1, clobber=True):
         self._metadata = OrderedDict()
         self._final_metadata = OrderedDict()
 
+        if blinding_offset_file is not None:
+            self._blinding_offsets = np.load(blinding_offset_file)
+        else:
+            self._blinding_offsets = None
+
     def _close(self):
         self._flush_metadata(self._final_metadata)
         self._final_metadata={}
@@ -126,8 +131,9 @@ def from_options(cls, options, resume=False):
         delimiter = options.get('delimiter', '\t')
         rank = options.get('rank', 0)
         nchain = options.get('parallel', 1)
+        blinding_offset_file = options.get('blinding_offsets', None)
         clobber = utils.boolean_string(options.get('clobber', True))
-        return cls(filename, rank, nchain, clobber=clobber)
+        return cls(filename, rank, nchain, clobber=clobber, blinding_offset_file=blinding_offset_file)
 
     @classmethod
     def load_from_options(cls, options):
diff --git a/cosmosis/output/in_memory_output.py b/cosmosis/output/in_memory_output.py
index 88dd8dc4..05162e43 100644
--- a/cosmosis/output/in_memory_output.py
+++ b/cosmosis/output/in_memory_output.py
@@ -3,13 +3,18 @@
 
 class InMemoryOutput(OutputBase):
     _aliases = ["memory"]
-    def __init__(self):
+    def __init__(self, blinding_offset_file=None):
         super(InMemoryOutput,self).__init__()
         self.rows = []
         self.meta = {}
         self.final_meta = {}
         self.comments = []
 
+        if blinding_offset_file is not None:
+            self._blinding_offsets = np.load(blinding_offset_file)
+        else:
+            self._blinding_offsets = None
+
     def _write_parameters(self, params):
         self.rows.append(params)
 
@@ -33,7 +38,8 @@ def __getitem__(self, key_or_index):
     def from_options(cls, options, resume=False):
         if resume:
             raise ValueError("Cannot resume from in-memory output")
-        return cls()
+        blinding_offset_file = options.get('blinding_offsets', None)
+        return cls(blinding_offset_file=blinding_offset_file)
 
     @classmethod
     def load_from_options(cls, options):
diff --git a/cosmosis/output/null_output.py b/cosmosis/output/null_output.py
index c1a7d60a..0c9fcafd 100644
--- a/cosmosis/output/null_output.py
+++ b/cosmosis/output/null_output.py
@@ -2,6 +2,13 @@
 
 class NullOutput(OutputBase):
     _aliases = ["none"]
+
+    def __init__(self, blinding_offset_file=None):
+        if blinding_offset_file is not None:
+            self._blinding_offsets = np.load(blinding_offset_file)
+        else:
+            self._blinding_offsets = None
+
     def _write_parameters(self, params):
         pass
 
@@ -18,7 +25,8 @@ def _write_final(self, key, value, comment):
     def from_options(cls, options, resume=False):
         if resume:
             raise ValueError("Cannot resume from null output")
-        return cls()
+        blinding_offset_file = options.get('blinding_offsets', None)
+        return cls(blinding_offset_file=blinding_offset_file)
 
     @classmethod
     def load_from_options(cls, options):
diff --git a/cosmosis/output/output_base.py b/cosmosis/output/output_base.py
index 9a4ade21..5c6e872f 100644
--- a/cosmosis/output/output_base.py
+++ b/cosmosis/output/output_base.py
@@ -136,6 +136,13 @@ def parameters(self, *param_groups):
         if not self.begun_sampling:
             self._begun_sampling(params)
             self.begun_sampling=True
+
+        #Blind output by applying offsets
+        if self._blinding_offsets is not None:
+            if len(self._blinding_offsets)!=len(params):
+                raise ValueError("Length of blinding offsets %d does not match number of output parameters %d"%(len(self._blinding_offsets), len(params)))
+            params+= self._blinding_offsets
+
         #Pass to the subclasses to write output
         self._write_parameters(params)
 
diff --git a/cosmosis/output/text_output.py b/cosmosis/output/text_output.py
index 73825faa..1a062540 100644
--- a/cosmosis/output/text_output.py
+++ b/cosmosis/output/text_output.py
@@ -13,7 +13,8 @@ class TextColumnOutput(OutputBase):
     FILE_EXTENSION = ".txt"
     _aliases = ["text", "txt"]
 
-    def __init__(self, filename, rank=0, nchain=1, delimiter='\t', lock=True, resume=False):
+    def __init__(self, filename, rank=0, nchain=1, delimiter='\t', lock=True, resume=False,
+                 blinding_offset_file=None):
         super(TextColumnOutput, self).__init__()
         self.delimiter = delimiter
 
@@ -46,6 +47,10 @@ def __init__(self, filename, rank=0, nchain=1, delimiter='\t', lock=True, resume
                 print("Note: You set resume=T but the file {} does not exist so I will start a new one".format(self._filename))
             self._file = open(self._filename, "w")
             self.resumed = False
+        if blinding_offset_file is not None:
+            self._blinding_offsets = np.load(blinding_offset_file)
+        else:
+            self._blinding_offsets = None
         if lock:
             try:
                 self.lock_file(self._file)
@@ -143,8 +148,10 @@ def from_options(cls, options, resume=False):
         delimiter = options.get('delimiter', '\t')
         rank = options.get('rank', 0)
         nchain = options.get('parallel', 1)
+        blinding_offset_file = options.get('blinding_offsets', None)
         lock = utils.boolean_string(options.get('lock', True))
-        return cls(filename, rank, nchain, delimiter=delimiter, lock=lock, resume=resume)
+        return cls(filename, rank, nchain, delimiter=delimiter, lock=lock, resume=resume,
+                   blinding_offset_file=blinding_offset_file)
 
     @classmethod
     def load_from_options(cls, options):