Extension of the "Veterans Choice" program could worry Democrats and other critics that Trump and Shulkin are inching toward sending some of the US$65.6 billion the department spends annually on medical care to corporations and private businesses.
During Wednesday's signing ceremony, Veterans Affairs Secretary David Shulkin praised the extension of the Veterans Choice program.
"The veterans have poured out their sweat and blood and tears for this country for so long, and it's time that they are recognized, and it's time that we now take care of them and take care of them properly", Mr. Trump said.
The 2014 initiative ensures that US veterans do not have to wait long periods of time or drive long distances to get their healthcare needs from a provider and can opt instead to receive healthcare from a local provider.
Veterans Choice was set to expire in August. Yet the program itself often encountered long wait times of its own.
Reforming the agency, rocked by a waiting-time scandal in 2014, was one of Trump's most-repeated campaign trail promises. The law also authorizes "the sharing of certain veterans' medical records with medical service providers outside the Department of Veterans Affairs".
"The Choice program was passed as a quick fix to the wait list manipulation scandal that broke three years ago", said Mark Lucas, executive director of Concerned Veterans for America.
"My father served in WWII and I proudly served in the United States Navy, and I appreciate President Trump's commitment to our military and our veterans". But bureaucratic problems have prevented many veterans from using the program.
"Congress now has some time to work with Secretary Shulkin on broader, more permanent choice reforms that will truly put the veteran at the center of their health care and remove VA bureaucrats as the middlemen", Lucas said.
Sen. John McCain, R-Ariz., said more than 1 million veterans have made 7 million appointments with health care providers in their communities under the Choice Program.
The head of a veterans advocacy group said much more needs to be done.