Delivering the Second Transforming India Lecture organised NITI Aayog on Thursday, Gates said that shift to digital transactions will enhance transparency and reduce leakages.
The Bill and Melinda Gates Foundation will also work closely with the IT Ministry on solutions for e-payment, digital health, and Digital literacy.
The IT Ministry has identified thousand villages which the foundation is keen on working with on e-agriculture.
Modi, in surprise decision on November 8, demonetised currency notes of Rs 500 and Rs 1,000 denomination, replacing them with new Rs 500 and Rs 2,000 bills.
"The Prime Minister's bold move to demonetise high-value denominations and replace with new notes with high security features is an important step to deflate India's shadow economy," Gates said.
India, he added, "has all the pieces in place for a compelling vision for digital financial inclusion. Aadhaar will convert a cumbersome, paper-based account opening process into a 30-second, all-digital system."
He was of the view that Aadhaar will also create a centralised data repository.
The impending rollout of payment banks and the ubiquity of mobile phones can enable access for all Indians to digital accounts connected to a fraud-resistant interoperable payment system, he said.
Referring to health issues in India, the Co-Chairman of the Bill and Melinda Gates Foundation said, "If I had a wand and could fix one health issue in India, it would be the malnutrition crisis. There are states that have made great progress, but there also are regions where malnutrition is the norm, not the exception."
Observing India has the largest number of stunted children in the world, he said, "If (malnutrition) is unaddressed, the lifetime earnings potential of children who suffer from malnutrition will cost the Indian economy a staggering USD 46 billion by 2030."
About 44 million children under the age of 5 are stunted, that is nearly four of every 10 children. Besides the huge toll this takes on children and their families, malnutrition takes a toll on the economy, he added.