Misleading thread title is misleading.
1) The US population will grow by at least 13% from 2012 to 2025, according to current demographic trends.
2) Life expectancy in the states has been continuously trending upward for the last century. In the recent past, it increased from 76.6 years on average in 2000 to 78.2 years on average in 2010. Most likely it will be around 80 years on average in 2025 (or more).
So, yes... we WILL need another 52,000 doctors in 2025.
It just has nothing to do with Obamacare.