Lack of interoperability between health data systems is a leading challenge for healthcare in the United States. This paper describes the challenges and lessons learned in the process of incorporating HL7 data and integration with Electronic Health Records and Health Information Exchanges from the perspective of a midsized Health Plan (Payer). As a Health Care Payer, Premera has a unique perspective regarding how health plans can provide the necessary data to complete the picture of care. This paper shares some of the best practices and focus areas for successful implementation of healthcare data integrations. This paper also focuses on integrating claims and clinical data using a master patient index as well as challenges faced in that process.Note that going forward `Health Plan' and `Payer' will be used interchangeably. Also, `Provider(s)', `Hospitals', `Healthcare Providers', `Clinics', `Provider Organizations' will be used interchangeably and in the context of this paper may mean the same.