In WA, the statute of limitations on a written agreement is generally 6 years. When a person gets medical help, the person often signs several documents. One of the documents likely has a promise to pay.
For an agreement not written down, the statute of limitations is generally 3 years.
Simply talking to someone does not restart the clock.
Determining whether the statute of limitations has expired is sometimes the central issue of an appeal. That is, it is sometimes not clear whether the time to sue has expired.
You can review your specific facts with your attorney to find out your legal options.
Disclaimer: This answer does not constitute legal advice. I am admitted in the States of New York, New Jersey and Massachusetts only and make no attempt to opine on matters of law that are not relevant to those three States. This advice is based on general principles of law that may or may not relate to your specific situation. Facts and laws change and these possible changes will affect the advice provided here. Consult an attorney in your locale before you act on any of this advice. You should not rely on this advice alone and nothing in these communications creates an attorney client relationship.