Over a working lifetime, that could add up significantly resulting in an earnings gap.
Researchers at George Mason University and Temple University found that a 25-year-old who negotiated a starting salary of $55,000, for example, will earn an extra $634,000 over their career. That's compared to someone who accepted an initial offer of $50,000, and it assumes a 5 percent average annual pay increase over a 40-year span.
"That gives you a good indication of why it's so important to start negotiations early in your career," explains Lydia Frank, a senior director at PayScale.com.
It may not be comfortable, but chances are it's worth asking.