Active duty members receive full medical and dental benefits as well as unlimited post exchange and commissary access. Active duty members may be stationed within the United States or abroad. ... Reserve duty members receive full medical and dental benefits only if called for active duty service.

See PDF:  https://giveanhour.org/wp-content/uploads/RCP-Fact-Sheet-2017-a.pdf

The Army Reserve constitutes some 20 percent of the Total Army force. Its 205,000 soldiers and 12,600 civilians provide 75 percent of key support units and capabilities such as logistics, medical, engineering, military information support, and civil affairs. It also includes structures such as voluntary public–private partnerships that amplify the total force’s capabilities, as well as certain unique capabilities not found
elsewhere in the military such as chemical companies able to detect biological weapons.

Since Desert Storm the Reserve and National Guard support more military deployment than any other time in history.  These Soldiers are called from their civilian families and civilian jobs.   Deployment creates issues in marriage relationship and distance from children.   Many reservists are the first to be lay off from civilian jobs -- Companies know it's illegal to fire Soldiers,but they can lay off.  The results in many Soldier facing issues with employment before and after deployments.   

For this reason, I feel that part-time Soldier should also have equal benefits as their full time counter parts -- at least after 10 years of service.