When it comes to negotiating salary, employees are zipping their lips. Recent research from Glassdoor found that 59 percent of American workers did not negotiate the salary in their most recent job. More than half the men and two-thirds of the women surveyed didn’t even attempt it! So over half of American employees are leaving money on the table, which can have lifelong implications on their careers.

Whether you’re a recent grad or a seasoned exec, salary negotiations give your career a leg up over its lifetime, and not just financially.

WHY YOU SHOULD NEGOTIATE SALARY

• Your salary follows you. The peskiest box on most job applications: Salary. If you haven’t negotiated your current salary, or if you’ve accepted less than you’re worth, that number sticks to you like a Band-Aid on an old wound. And it will lower your starting value to be able to negotiate more at your next employer.
• Negotiating determines your long-term income. But will it really hurt if you accepted the first offer from that employer right out of college? Well, maybe. Statistics suggest that consistent negotiators earn much more during their careers: executives who negotiated that first post-college salary earned a half-million more dollars during their careers than their non-negotiating counterparts. Female workers who consistently negotiated earned a full million dollars more than their non-negotiating counterparts. Negotiate now, earn more later.
• You know your worth. And no one else will know your worth unless you do. Negotiating shows you’re capable and confident in your skills, and that you’ve done your homework to know their value. Accepting less than you’re worth will only start your morale on the wrong foot.
• It doesn’t hurt to ask. Rather than accept a low offer with bitterness or decline it with indignation, why not ask for your desired compensation? It’s worth a shot—you already know the company wants you. The worst you could hear is a “no.” But you could also hear a “no, but…” or even a “yes.”

HOW TO NEGOTIATE SALARY

• Do your homework. Know what your position is worth for your field, level of experience, and geographic location. You might even be able to find the salary range within the company.
• Let them go first. It can be tough to evade questions about salary, but it’s critical to let the employer make the first offer. (It may help to insist that you’re more interested in working at the company, and that you’ll consider any reasonable offer.) This gives you an idea of their hand without first revealing yours.
• Highlight your selling points. Never blindly ask for more money! Be prepared with a justification for the bump, including whether the initial offer was below market value.
• Focus on the total compensation. Salary is not the only thing that matters to a new employee—there’s also benefits, bonuses, and perks like telecommuting or flex-time. Maybe the salary can’t get sweeter, but something else can.

And it should go without saying, don’t “negotiate” salary, benefits, or time off until you have a written job offer. Recruiters don’t appreciate candidates who make demands before they’ve proven their value! But once you’ve shown you’re the right person for the job, unzip your lips and negotiate. Your career will thank you later.