diff --git a/src/math-util.inc b/src/math-util.inc
index b7815c8f..0133a488 100644
--- a/src/math-util.inc
+++ b/src/math-util.inc
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "prim-types.hh"
+//#include "prim-types.hh"
 #include "value-types.hh"
 
 namespace tinyusdz {
diff --git a/src/prim-types.hh b/src/prim-types.hh
index 54f87382..a0d921d0 100644
--- a/src/prim-types.hh
+++ b/src/prim-types.hh
@@ -46,6 +46,7 @@
 #include "primvar.hh"
 //
 #include "value-eval-util.hh"
+#include "math-util.inc"
 
 namespace tinyusdz {
 
@@ -1310,6 +1311,37 @@ struct TypedTimeSamples {
     _dirty = true;
   }
 
+  bool has_sample_at(const double t) const {
+    if (_dirty) {
+      update();
+    }
+
+    const auto it = std::find_if(_samples.begin(), _samples.end(), [&t](const Sample &s) {
+      return tinyusdz::math::is_close(t, s.t);
+    });
+
+    return (it != _samples.end());
+  }
+
+  bool get_sample_at(const double t, Sample **dst) {
+    if (!dst) {
+      return false;
+    }
+
+    if (_dirty) {
+      update();
+    }
+
+    const auto it = std::find_if(_samples.begin(), _samples.end(), [&t](const Sample &sample) {
+      return math::is_close(t, sample.t);
+    });
+
+    if (it != _samples.end()) {
+      (*dst) = &(*it); 
+    }
+    return false;
+  }
+
   const std::vector<Sample> &get_samples() const {
     if (_dirty) {
       update();
diff --git a/src/usdGeom.cc b/src/usdGeom.cc
index 35ab05cc..a5d95a5f 100644
--- a/src/usdGeom.cc
+++ b/src/usdGeom.cc
@@ -305,6 +305,41 @@ bool GeomPrimvar::flatten_with_indices(const double t, std::vector<T> *dest, con
   return false;
 }
 
+std::vector<int32_t> GeomPrimvar::get_indices(const double t) const {
+  if (value::TimeCode(t).is_default()) {
+    if (has_default_indices()) {
+      return get_default_indices();
+    }
+  }
+  
+  if (has_timesampled_indices()) {
+    std::vector<int32_t> indices;
+    if (get_timesampled_indices().get(&indices, t)) {
+      return indices;
+    }
+  }
+
+  if (has_default_indices()) {
+    return get_default_indices();
+  }
+
+  return std::vector<int32_t>();
+}
+
+void GeomPrimvar::set_indices(const std::vector<int32_t> &indices, const double t) {
+  if (value::TimeCode(t).is_default()) {
+    _indices = indices;
+  } else {
+    TypedTimeSamples<std::vector<int32_t>>::Sample *psample{nullptr};
+    if (_ts_indices.get_sample_at(t, &psample)) {
+      // overwrite content
+      psample->value = indices;
+    } else {
+      _ts_indices.add_sample(t, indices);
+    }
+  }
+}
+
 template <typename T>
 bool GeomPrimvar::flatten_with_indices(std::vector<T> *dest, std::string *err) const {
   return flatten_with_indices(value::TimeCode::Default(), dest, value::TimeSampleInterpolationType::Linear, err);
diff --git a/src/usdGeom.hh b/src/usdGeom.hh
index a8b8ad8c..d4269b34 100644
--- a/src/usdGeom.hh
+++ b/src/usdGeom.hh
@@ -182,6 +182,11 @@ class GeomPrimvar {
     _unauthoredValuesIndex = n;
   }
 
+  ///
+  /// Get indices at specified timecode.
+  /// Returns empty when appropriate indices does not exist for timecode 't'.
+  ///
+  std::vector<int32_t> get_indices(const double t = value::TimeCode::Default()) const;
   
   const std::vector<int32_t> &get_default_indices() const {
     return _indices;
@@ -266,6 +271,11 @@ class GeomPrimvar {
 
   void set_name(const std::string &name) { _name = name; }
 
+  // Set indices for specified timecode 't'
+  // indices will be replaced when there is an indices at timecode 't'.
+  void set_indices(const std::vector<int32_t> &indices, const double t = value::TimeCode::Default());
+
+
   void set_default_indices(const std::vector<int32_t> &indices) {
     _indices = indices;
   }
diff --git a/src/value-types.cc b/src/value-types.cc
index d441e71c..1febf030 100644
--- a/src/value-types.cc
+++ b/src/value-types.cc
@@ -9,6 +9,7 @@
 
 //
 #include "common-macros.inc"
+#include "math-util.inc"
 
 // For compile-time map
 // Another candidate is frozen: https://github.com/serge-sans-paille/frozen
@@ -1075,5 +1076,36 @@ bool FlexibleTypeCast(const value::Value &src, value::Value &dst) {
 }
 #endif
 
+bool TimeSamples::has_sample_at(const double t) const {
+  if (_dirty) {
+    update();
+  }
+
+  const auto it = std::find_if(_samples.begin(), _samples.end(), [&t](const Sample &s) {
+    return math::is_close(t, s.t);
+  });
+
+  return (it != _samples.end());
+}
+
+bool TimeSamples::get_sample_at(const double t, Sample **dst) {
+  if (!dst) {
+    return false;
+  }
+
+  if (_dirty) {
+    update();
+  }
+
+  const auto it = std::find_if(_samples.begin(), _samples.end(), [&t](const Sample &sample) {
+    return math::is_close(t, sample.t);
+  });
+
+  if (it != _samples.end()) {
+    (*dst) = &(*it); 
+  }
+  return false;
+}
+
 }  // namespace value
 }  // namespace tinyusdz
diff --git a/src/value-types.hh b/src/value-types.hh
index 467fd6ff..5b6be1d2 100644
--- a/src/value-types.hh
+++ b/src/value-types.hh
@@ -2290,6 +2290,9 @@ struct TimeSamples {
     _dirty = false;
   }
 
+  bool has_sample_at(const double t) const;
+  bool get_sample_at(const double t, Sample **s);
+
   nonstd::optional<double> get_time(size_t idx) const {
     if (idx >= _samples.size()) {
       return nonstd::nullopt;