diff --git a/include/openthread/coap.h b/include/openthread/coap.h
index 3ac7067ce..fe9dc1e4d 100644
--- a/include/openthread/coap.h
+++ b/include/openthread/coap.h
@@ -148,6 +148,20 @@ typedef struct otCoapOption
     const uint8_t *mValue;   ///< A pointer to the Option Value
 } otCoapOption;
 
+/**
+ * CoAP Content Format codes.  The full list is documented at
+ * https://tools.ietf.org/html/rfc7252#page-92
+ */
+typedef enum otCoapOptionContentFormat
+{
+    OT_COAP_OPTION_CONTENT_FORMAT_TEXT_PLAIN    = 0,    ///< text/plain
+    OT_COAP_OPTION_CONTENT_FORMAT_LINK_FORMAT   = 40,   ///< application/link-format
+    OT_COAP_OPTION_CONTENT_FORMAT_XML           = 41,   ///< application/xml
+    OT_COAP_OPTION_CONTENT_FORMAT_OCTET_STREAM  = 42,   ///< application/octet-stream
+    OT_COAP_OPTION_CONTENT_FORMAT_EXI           = 47,   ///< application/exi
+    OT_COAP_OPTION_CONTENT_FORMAT_JSON          = 50,   ///< application/json
+} otCoapOptionContentFormat;
+
 #define OT_COAP_HEADER_MAX_LENGTH       128  ///< Max CoAP header length (bytes)
 
 /**
@@ -244,6 +258,26 @@ void otCoapHeaderSetToken(otCoapHeader *aHeader, const uint8_t *aToken, uint8_t
  */
 void otCoapHeaderGenerateToken(otCoapHeader *aHeader, uint8_t aTokenLength);
 
+/**
+ * This function appends the Content Format CoAP option as specified in
+ * https://tools.ietf.org/html/rfc7252#page-92.  This *must* be called before
+ * setting otCoapHeaderSetPayloadMarker if a payload is to be included in the
+ * message.
+ *
+ * The function is a convenience wrapper around otCoapHeaderAppendUintOption,
+ * and if the desired format type code isn't listed in otCoapOptionContentFormat,
+ * this base function should be used instead.
+ *
+ * @param[inout]  aHeader           A pointer to the CoAP header.
+ * @param[in]     aContentFormat    One of the content formats listed in
+ *                                  otCoapOptionContentFormat above.
+ *
+ * @retval OT_ERROR_NONE          Successfully appended the option.
+ * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+ * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+ */
+otError otCoapHeaderAppendContentFormatOption(otCoapHeader *aHeader, otCoapOptionContentFormat aContentFormat);
+
 /**
  * This function appends a CoAP option in a header.
  *
diff --git a/src/core/api/coap_api.cpp b/src/core/api/coap_api.cpp
index 4c913fec9..60c67e60b 100644
--- a/src/core/api/coap_api.cpp
+++ b/src/core/api/coap_api.cpp
@@ -58,6 +58,11 @@ void otCoapHeaderGenerateToken(otCoapHeader *aHeader, uint8_t aTokenLength)
     static_cast<Coap::Header *>(aHeader)->SetToken(aTokenLength);
 }
 
+otError otCoapHeaderAppendContentFormatOption(otCoapHeader *aHeader, otCoapOptionContentFormat aContentFormat)
+{
+    return static_cast<Coap::Header *>(aHeader)->AppendContentFormatOption(aContentFormat);
+}
+
 otError otCoapHeaderAppendOption(otCoapHeader *aHeader, const otCoapOption *aOption)
 {
     return static_cast<Coap::Header *>(aHeader)->AppendOption(*static_cast<const Coap::Header::Option *>(aOption));
diff --git a/src/core/coap/coap_header.cpp b/src/core/coap/coap_header.cpp
index 9edf0ce38..294d2cf3a 100644
--- a/src/core/coap/coap_header.cpp
+++ b/src/core/coap/coap_header.cpp
@@ -313,9 +313,9 @@ exit:
     return error;
 }
 
-otError Header::AppendContentFormatOption(MediaType aType)
+otError Header::AppendContentFormatOption(otCoapOptionContentFormat aContentFormat)
 {
-    return AppendUintOption(OT_COAP_OPTION_CONTENT_FORMAT, aType);
+    return AppendUintOption(OT_COAP_OPTION_CONTENT_FORMAT, static_cast<uint32_t>(aContentFormat));
 }
 
 otError Header::AppendMaxAgeOption(uint32_t aMaxAge)
diff --git a/src/core/coap/coap_header.hpp b/src/core/coap/coap_header.hpp
index 7452859bf..ceaa4e2de 100644
--- a/src/core/coap/coap_header.hpp
+++ b/src/core/coap/coap_header.hpp
@@ -310,26 +310,17 @@ public:
      */
     otError AppendUriPathOptions(const char *aUriPath);
 
-    /**
-     * Media Types
-     *
-     */
-    enum MediaType
-    {
-        kApplicationOctetStream = 42,  ///< application/octet-stream
-    };
-
     /**
      * This method appends a Content-Format option.
      *
-     * @param[in]  aType  The Media Type value.
+     * @param[in]  aContentFormat  The Content Format value.
      *
      * @retval OT_ERROR_NONE          Successfully appended the option.
      * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
      * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
      *
      */
-    otError AppendContentFormatOption(MediaType aType);
+    otError AppendContentFormatOption(otCoapOptionContentFormat aContentFormat);
 
     /**
      * This method appends a Max-Age option.