Greetings Stacey,
If your site is built on WordPress, you can use the Yoast SEO plugin and set categories to "noindex". You can find this in the menu for "Titles &Metas" and then "Taxonomies" in the Yoast plugin. I did that recently for tags, categories and archives within a client's blog to remove duplicate content notices in my Moz reports.
That being said, it MAY have some impact on your position in the SERPs.
I hope that helps.
Best Regards,
Mark
