diff --git a/fields.js b/fields.js
index 5af6f64..9890898 100644
--- a/fields.js
+++ b/fields.js
@@ -5,7 +5,7 @@ const schema = require("./schema");
  * @see https://apple.co/2wkUBd
  */
 
-class FieldsArea {
+class FieldsContainer {
 	constructor() {
 		this.fields = [];
 	}
@@ -57,7 +57,21 @@ class FieldsArea {
 	}
 }
 
+class StringField {
+	set transitType(v) {
+		if (schema.isValid(v, schema.constants.transitType, true)) {
+			this.fields = v;
+		} else {
+			this.fields = this.fields && this.fields !== "" ? this.fields : "";
+		}
+	}
+	get transitType() {
+		return this.fields;
+	}
+}
+
 module.exports = {
 	areas: ["primaryFields", "secondaryFields", "auxiliaryFields", "backFields", "headerFields"],
-	FieldsArea
+	FieldsContainer,
+	StringField
 };
diff --git a/index.js b/index.js
index b467644..b916862 100644
--- a/index.js
+++ b/index.js
@@ -6,7 +6,7 @@ const forge = require("node-forge");
 const archiver = require("archiver");
 const moment = require("moment");
 const schema = require("./schema");
-const fields = require("./fields");
+const { areas: fieldsName, FieldsContainer, StringField } = require("./fields");
 const { errors, warnings } = require("./messages");
 
 const readdir = util.promisify(fs.readdir);
@@ -21,7 +21,8 @@ class Pass {
 		this.props = {};
 		this.shouldOverwrite = !(this.options.hasOwnProperty("shouldOverwrite") && !this.options.shouldOverwrite);
 
-		fields.areas.forEach(a => this[a] = new fields.FieldsArea());
+		fieldsName.forEach(a => this[a] = new FieldsContainer());
+		this.transitType = new StringField();
 	}
 
 	/**
@@ -523,12 +524,18 @@ class Pass {
 			});
 		}
 
-		fields.areas.forEach(area => {
+		fieldsName.forEach(area => {
 			if (this[area].fields.length) {
 				passFile[this.type][area].push(...this[area].fields);
 			}
 		});
 
+		if (this.type === "boardingPass" && this.transitType) {
+			passFile[this.type]["transitType"] = this.transitType;
+		} else {
+			throw new Error("Cannot proceed with pass creation. transitType field is required for boardingPasses.");
+		}
+
 		return Promise.resolve(Buffer.from(JSON.stringify(passFile)));
 	}
 
diff --git a/schema.js b/schema.js
index 46b1b4b..7ec2412 100644
--- a/schema.js
+++ b/schema.js
@@ -66,7 +66,8 @@ module.exports = {
 		basicStructure,
 		boardingStructure,
 		beaconsDict,
-		locationsDict
+		locationsDict,
+		transitType
 	},
 	isValid: (opts, schemaName, debug = false) => {
 		let validation = Joi.validate(opts, schemaName);