diff --git a/lib/Deprecated.js b/lib/Deprecated.js
index de696348..e23ad97c 100644
--- a/lib/Deprecated.js
+++ b/lib/Deprecated.js
@@ -64,16 +64,46 @@ class iPgm {
     * @param {string | array} data
     * @param {string} [type]
     * @param {object} options
-    * @param {*} inDs
     */
-  addParam(data, type, options, inDs) {
-    if (!Array.isArray(data) && !type) {
-      iPgmDeprecate('defaulting parameter type to 1024a has been deprecated. You should specify a type instead.');
-      // eslint-disable-next-line no-param-reassign
-      type = '1024a';
+  addParam(data, type, options) {
+    const parameter = {};
+
+    if (Array.isArray(data)) { // DS parameter
+      parameter.type = 'ds';
+      parameter.fields = [];
+
+      if (typeof type === 'object') { // <ds> options
+        Object.keys(type).forEach((key) => {
+          parameter[key] = type[key];
+        });
+      }
+      // convert 2D Array into fields [] of data objects
+      for (let i = 0; i < data.length; i += 1) {
+        const field = { type: data[i][1], value: data[i][0] };
+        if (typeof data[i][2] === 'object') {
+          Object.keys(data[i][2]).forEach((key) => { // <data> options
+            field[key] = data[i][2][key];
+          });
+        }
+        parameter.fields.push(field);
+      }
+    } else {
+      parameter.type = type;
+      parameter.value = data;
+      if (!type) {
+        iPgmDeprecate('defaulting parameter type to 1024a has been deprecated. You should specify a type instead.');
+        parameter.type = '1024a';
+      }
+
+      if (typeof options === 'object') { // <data> options
+        Object.keys(options).forEach((key) => {
+          parameter[key] = options[key];
+        });
+      }
     }
+
     iPgmDeprecate('As of v1.0, \'iPgm.addParam()\' is deprecated. Please use \'ProgramCall.addParam()\' instead.');
-    return this.ProgramCall.addParam(data, type, options, inDs);
+    return this.ProgramCall.addParam(parameter);
   }
 
   /**
diff --git a/lib/ProgramCall.js b/lib/ProgramCall.js
index 71188c87..fb726d7f 100644
--- a/lib/ProgramCall.js
+++ b/lib/ProgramCall.js
@@ -16,6 +16,8 @@
 // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+/* eslint-disable no-underscore-dangle */
+
 class ProgramCall {
   /**
    * @description creates a new ProgramCall object
@@ -31,59 +33,62 @@ class ProgramCall {
   }
 
   /**
-    * @description adds a parameter to the program XML
-    * @param {string | array} data
-    * @param {string} [type]
-    * @param {object} options
-    * @param {*} inDs
-    */
-  addParam(data, type, options, inDs = null) {
-    let opt;
-    // DS element has no 'type', so if the second param 'type' is an Object, then it is the options.
-    if (Array.isArray(data)) {
-      opt = type;
-    } else {
-      opt = options;
-      if (type === undefined) {
-        throw new Error('Specifying the parameter type is required.');
-      }
-    }
-    if (!inDs) { // In recursive mode, if it is an element in DS, then no <parm> or </parm> needed.
-      this.xml += '<parm';
-      if (opt && typeof opt === 'object') { // append <param> options
-        if (opt.io) { this.xml += ` io='${opt.io}'`; }
-        if (opt.by) { this.xml += ` by='${opt.by}'`; }
-      }
-      this.xml += '>';
-    }
-
-    if (Array.isArray(data)) { // If it is a struct parameter, recursively parse its children.
+   * Internal function to handle ds and data within <parm> node
+   * There is an open propsal to add private methods to JS.
+   * https://github.com/tc39/proposal-private-methods
+   * We should update to use private methods in the future.
+   * @param {object} data
+   */
+  __addData__(data = {}) {
+    if (data.type === 'ds') {
       this.xml += '<ds';
-      if (opt && typeof opt === 'object') { // append <ds> options
-        if (opt.dim) { this.xml += ` dim='${opt.dim}'`; }
-        if (opt.dou) { this.xml += ` dou='${opt.dou}'`; }
-        if (opt.len) { this.xml += ` len='${opt.len}'`; }
-        if (opt.data) { this.xml += ` data='${opt.data}'`; }
-      }
+      // append <ds> options
+      if (data.name) { this.xml += ` name='${data.name}'`; }
+      if (data.dim) { this.xml += ` dim='${data.dim}'`; }
+      if (data.dou) { this.xml += ` dou='${data.dou}'`; }
+      if (data.len) { this.xml += ` len='${data.len}'`; }
+      if (data.data) { this.xml += ` data='${data.data}'`; }
       this.xml += '>';
 
-      for (let i = 0; i < data.length; i += 1) {
-        this.addParam(data[i][0], data[i][1], data[i][2], true);
+      for (let i = 0; i < data.fields.length; i += 1) {
+        this.__addData__(data.fields[i]);
       }
       this.xml += '</ds>';
-    } else { // A simple parameter
-      this.xml += `<data type='${type}'`;
-      if (opt && typeof opt === 'object') { // append <data> options
-        Object.keys(opt).forEach((key) => {
-          this.xml += ` ${key}='${opt[key]}'`;
-        });
-      }
-      this.xml += `>${data}</data>`;
+    } else {
+      this.xml += `<data type='${data.type}'`;
+      // append <data> options
+      if (data.name) { this.xml += ` name='${data.name}'`; }
+      if (data.varying) { this.xml += ` varying='${data.varying}'`; }
+      if (data.enddo) { this.xml += ` enddo='${data.enddo}'`; }
+      if (data.setlen) { this.xml += ` setlen='${data.setlen}'`; }
+      if (data.offset) { this.xml += ` offset='${data.offset}'`; }
+      if (data.hex) { this.xml += ` hex='${data.hex}'`; }
+      if (data.trim) { this.xml += ` trim='${data.trim}'`; }
+      if (data.next) { this.xml += ` next='${data.next}'`; }
+      this.xml += `>${data.value}</data>`;
     }
+  }
 
-    if (!inDs) { // In recursive mode, if it is an element in DS, then no <parm> or </parm> needed.
-      this.xml += '</parm>';
+  /**
+  * @description adds a parameter to the program XML
+  * @param {object} parmeter
+  */
+  addParam(parameter = {}) {
+    if (typeof parameter !== 'object') {
+      throw new Error('Expected the first parameter to be an object');
+    }
+    if (parameter.type === undefined) {
+      throw new Error('Expected \'type\' key on the parameter object');
     }
+    this.xml += '<parm';
+
+    if (parameter.name) { this.xml += ` name='${parameter.name}'`; }
+    if (parameter.io) { this.xml += ` io='${parameter.io}'`; }
+    if (parameter.by) { this.xml += ` by='${parameter.by}'`; }
+
+    this.xml += '>';
+    this.__addData__(parameter);
+    this.xml += '</parm>';
   }
 
   /**
diff --git a/test/unit/ProgamCallUnit.js b/test/unit/ProgamCallUnit.js
index 9fbaaae9..f881a6f9 100644
--- a/test/unit/ProgamCallUnit.js
+++ b/test/unit/ProgamCallUnit.js
@@ -23,20 +23,20 @@ const { expect } = require('chai');
 const { ProgramCall } = require('../../lib/itoolkit');
 
 const outBuf = [
-  [0, '10i0'],
-  [0, '10i0'],
-  ['', '36h'],
-  ['', '10A'],
-  ['', '1A'],
-  ['', '1A'],
-  [0, '10i0'],
-  [0, '10i0'],
+  { type: '10i0', value: 0 },
+  { type: '10i0', value: 0 },
+  { type: '36h', value: '' },
+  { type: '10A', value: '' },
+  { type: '1A', value: '' },
+  { type: '1A', value: '' },
+  { type: '10i0', value: 0 },
+  { type: '10i0', value: 0 },
 ];
 const errno = [
-  [0, '10i0'],
-  [0, '10i0', { setlen: 'rec2' }],
-  ['', '7A'],
-  ['', '1A'],
+  { type: '10i0', value: 0 },
+  { type: '10i0', value: 0, setlen: 'rec2' },
+  { type: '7A', value: '' },
+  { type: '1A', value: '' },
 ];
 
 describe('ProgramCall Class Unit Tests', () => {
@@ -71,7 +71,7 @@ describe('ProgramCall Class Unit Tests', () => {
           error: 'fast',
         });
 
-      pgm.addParam(outBuf, { io: 'out' });
+      pgm.addParam({ type: 'ds', io: 'out', fields: outBuf });
 
       let expectedXML = '<pgm name=\'QTOCNETSTS\' lib=\'QSYS\' func=\'QtoRtvTCPA\' error=\'fast\'>'
       + '<parm io=\'out\'><ds><data type=\'10i0\'>0</data><data type=\'10i0\'>'
@@ -81,7 +81,7 @@ describe('ProgramCall Class Unit Tests', () => {
 
       expect(pgm.toXML()).to.equal(expectedXML);
 
-      pgm.addParam(66, '10i0');
+      pgm.addParam({ value: 66, type: '10i0' });
 
       expectedXML = '<pgm name=\'QTOCNETSTS\' lib=\'QSYS\' func=\'QtoRtvTCPA\' error=\'fast\'>'
       + '<parm io=\'out\'><ds><data type=\'10i0\'>0</data><data type=\'10i0\'>'
@@ -92,7 +92,7 @@ describe('ProgramCall Class Unit Tests', () => {
 
       expect(pgm.toXML()).to.equal(expectedXML);
 
-      pgm.addParam(1, '10i0');
+      pgm.addParam({ value: 1, type: '10i0' });
 
       expectedXML = '<pgm name=\'QTOCNETSTS\' lib=\'QSYS\' func=\'QtoRtvTCPA\' error=\'fast\'>'
       + '<parm io=\'out\'><ds><data type=\'10i0\'>0</data><data type=\'10i0\'>'
@@ -104,7 +104,7 @@ describe('ProgramCall Class Unit Tests', () => {
 
       expect(pgm.toXML()).to.equal(expectedXML);
 
-      pgm.addParam('QCCSID', '10A');
+      pgm.addParam({ value: 'QCCSID', type: '10A' });
 
       expectedXML = '<pgm name=\'QTOCNETSTS\' lib=\'QSYS\' func=\'QtoRtvTCPA\' error=\'fast\'>'
       + '<parm io=\'out\'><ds><data type=\'10i0\'>0</data><data type=\'10i0\'>'
@@ -117,7 +117,9 @@ describe('ProgramCall Class Unit Tests', () => {
 
       expect(pgm.toXML()).to.equal(expectedXML);
 
-      pgm.addParam(errno, { io: 'both', len: 'rec2' });
+      pgm.addParam({
+        type: 'ds', io: 'both', len: 'rec2', fields: errno,
+      });
 
       expectedXML = '<pgm name=\'QTOCNETSTS\' lib=\'QSYS\' func=\'QtoRtvTCPA\' error=\'fast\'>'
       + '<parm io=\'out\'><ds><data type=\'10i0\'>0</data><data type=\'10i0\'>'
@@ -137,8 +139,8 @@ describe('ProgramCall Class Unit Tests', () => {
     it('regular <parm> contains by=\'val\'', () => {
       const pgm = new ProgramCall('MYPGM', { lib: 'MYLIB', func: 'MY_PROCEDURE' });
 
-      pgm.addParam('', '1A', { by: 'val' });
-      pgm.addReturn('', '2A', { name: 'output' });
+      pgm.addParam({ value: '', type: '1A', by: 'val' });
+      pgm.addReturn('', '2A', 'output');
 
       const lookAtXML = pgm.toXML();
       expect(lookAtXML).to.match(/<parm .*by='val'.*>/);
@@ -148,11 +150,13 @@ describe('ProgramCall Class Unit Tests', () => {
       const pgm = new ProgramCall('MYPGM', { lib: 'MYLIB', func: 'MY_PROCEDURE' });
 
       const params = [
-        [0, '3s0'],
-        [0, '7s0', { name: 'ds_fld2' }],
+        { type: '3s0', value: 0 },
+        { type: '7s0', value: 0, name: 'ds_fld2' },
       ];
 
-      pgm.addParam(params, { name: 'inds', by: 'val' });
+      pgm.addParam({
+        name: 'inds', type: 'ds', by: 'val', fields: params,
+      });
       pgm.addReturn('', '2A', { name: 'output' });
 
       const lookAtXML = pgm.toXML();
@@ -162,7 +166,9 @@ describe('ProgramCall Class Unit Tests', () => {
     it('regular <parm> contains by=\'val\', with io=\'both\'', () => {
       const pgm = new ProgramCall('MYPGM', { lib: 'MYLIB', func: 'MY_PROCEDURE' });
 
-      pgm.addParam('', '1A', { by: 'val', io: 'both' });
+      pgm.addParam({
+        value: '', type: '1A', by: 'val', io: 'both',
+      });
       pgm.addReturn('', '2A', { name: 'output' });
 
       const lookAtXML = pgm.toXML();
@@ -174,11 +180,13 @@ describe('ProgramCall Class Unit Tests', () => {
       const pgm = new ProgramCall('MYPGM', { lib: 'MYLIB', func: 'MY_PROCEDURE' });
 
       const params = [
-        [0, '3s0'],
-        [0, '7s0', { name: 'ds_fld2' }],
+        { type: '3s0', value: 0 },
+        { type: '7s0', value: 0, name: 'ds_fld2' },
       ];
 
-      pgm.addParam(params, { name: 'inds', by: 'val', io: 'both' });
+      pgm.addParam({
+        name: 'inds', type: 'ds', by: 'val', io: 'both', fields: params,
+      });
       pgm.addReturn('', '2A', { name: 'output' });
 
       const lookAtXML = pgm.toXML();