Legal Question in Civil Litigation in Maryland

If you submitted a bill with a payment due date, I would consider the due date as the tolling of the statute, which would mean you should sue within 3 years of that date. If at any time thereafter the parents acknowledged the debt even though they are refusing to pay it, the statute would reset as of the date of acknowledgement. Even if you are beyond that date you can still sue, since the statute of limitations is an affirmative defense, which means that the defendant has to raise it in their response. If your suit is for less than $30000 you can sue in the District Court of Maryland and if the defendants don't file a timely notice to defend, you can get a judgment against them regardless of the limitations issue.

Even though you didn't have a signed contract, if you had to sue you would do so on either or both of 2 theories--an oral contract, since it was understood that the services were being performed with the expectation of payment, and quantum meruit, which is a latin "lawyer" phrase meaning you are suing for the value of services rendered. Of course, assuming there was no prediscussion of pricing, you would have to demonstrate that your claim is your usual charges for the services performed.

Mr. Sher's response is well-reasoned but I would add that the deadline for filing the non-contract claims (like unjust enrichment or quantum meruit which are slightly different but both "fairness" claims) would likely be three years from the date services were rendered and waiting could prevent recovery. In a quantum meruit case, the value is the gain to the person who got the services, not the loss to the person who performed them. So typically the discussion does not revolve around the going rate but rather what benefit the non-paying party received. In some cases, those two concepts are quite similar, in others quite different.

While I hope this general legal information helps, it doesn't substitute for legal advice.