Small Medium Enterprises (SME) and Large Medium Enterprises (LME) have experienced a decline in revenues and profits as a result of the Covid-19 pandemic in Indonesia. Various efforts have been made by the Indonesian government to restore Indonesia’s economic conditions, including the recovery of the Micro, Small, and Medium Enterprises (MSME) business. This research was conducted to find the main cause of the decline in the income of SME and LME during the Covid-19 pandemic in Indonesia to then get the proper business strategy which can be applied by business practitioners on SME and LME so that they can maintain their business sustainability during the Covid-19 pandemic and the new normal era in Indonesia. The results of this study indicate that the decline in the income of SME and LME is mostly caused by a drastic decrease in the number of sales of products and services because consumers, especially millennial consumers, experience changes in behavior during the pandemic, namely buying products online, using social media, -especially Instagram- to get references for their online purchases, and using the Cash on Delivery (COD) payment method, which shows that financial literacy in Indonesia is not good enough. To be able to increase the income of SME and LME in the new normal era, it is recommended that business people sell their products and services online through various social media which are often accessed by consumers, especially millennials as potential buyers. Moreover, it requires the participation of the government and universities in improving the financial literacy of the Indonesian people to support the business climate in Indonesia.