The United States military draft as it exists in 2019 is merely a placeholder system, collecting names and identifying details on young male citizens and immigrants beginning at the age of 18. If the United States ever returns to war, the physical draft could well be reinstated. Those who want to avoid going to war would have to make a difficult choice. There are two different paths to follow when avoiding being called for the draft: legal methods (or draft avoidance), and illegal methods, called draft evasion or draft dodging. The results of these two courses of action would be, of course, very different.
TL;DR (Too Long; Didn't Read)
All males who live in the United States are required to register for Selective Service, or the draft, within one month of their 18th birthday. Those who refuse to register can be charged with a felony and can receive fines, a prison sentence or other forms of punishment.
Current History of the Draft
The last time the draft was used to create an actual fighting force in this country was during the Vietnam War. During that time, a large number of young men refused to go to war, using a variety of methods for avoiding, or dodging, the draft. Some slipped over the border into Canada, some claimed bogus medical conditions such as ulcers or bone spurs, and some even claimed to be homosexual, which was a disqualifying reason at the time.
For those who want to avoid fighting, for whatever reason, there are a wide variety of legal methods to get out of actively participating in a war. If you are a member of certain churches known as Peach Churches, you can join the military in a non-combatant role such as medic or chaplain.
People who object strenuously to any type of involvement in the military are allowed to serve in an Alternate Service Program, contributing to the national health and safety in other ways in order to fulfill their draft commitment. Some alternate service areas include hospital work, scientific research, teaching and teacher's aids, poverty relief and juvenile rehab programs. Those placed in the Alternate Service Program will be assigned, as closely as possible, to work that fits in with their talents and interests.
Draft Evasion Penalty
There is a seemingly endless list of creative ways in which draft dodgers avoided going to war during the Vietnam Era, and future generations will doubtless be just as creative. Even today's young men, who are required to register within a month of their 18th birthday, sometimes avoid registering by various means. The method used really doesn't matter, because the penalty remains the same. If you're tried and convicted of failing to comply with the Military Selective Service Act, you will be guilty of a felony offense. You could be subject to a fine of up to a quarter of a million dollars, a prison term of up to five years, or both.
Signing up with Selective Service is such a rite of passage for young men in this country that, even if one manages to slip by until the age of 26 (the draft cut-off date) without being prosecuted, he could find financial and employment doors permanently closed to him. He'll never be able to qualify for a federal education grant or loan, never become a citizen if he's an immigrant, never get federal jobs training and never work for any U.S. government job.