Does anyone know what laws, if any, are applicable to being reimbursed for expenses in CO? I was recently laid off by a large Medical center and they have not reimbursed expenses that were approved by my manager, dating back to June. I have checked with several people in the accounting department, who all say that they have forwarded on to other people of approvals and signiatures, but no checks ever come. I've left messages with the Director of HR, and am now not getting any calls back. Any advice would be helpful.

There are only two states where reimbursements are required by law, and Colorado is neither of them. Did you have a written agreement with your employer about it and if so, what does it say?

California and (in some cases, Massachusetts) are the only states which have wage and hour laws requiring expense reimbursements.

I would send a certified, return receipt requested, letter to the Accounting Manager. If you have an agreement that such expenses will be reimbursed, include a copy.

Agreed with the other two answers. However those are labor law answers and not all laws are labor law. If (hypothetically speaking) we were neighbors, your house was broken in to and I in good faith went to the store to buy you a new door while you guarding the broken door at your house. If you later refused to reimburse me I could take you to small claims court with a good chance of winning. Your chances with your employer using a similar argument are no worse then this example even though CO does not have a labor law remedy.

That's why I was asking about any agreements there might be.

Sure, although agreements can be implied. If the employer (for example) sends an employee on a trip to Denver, it would be difficult for the employer to later argue that the employer by sending the employee on a trip has somehow failed to agree to pay for necessary expenses. On the other hand (for example) if I think I need a $1,200 chair at work, the employer's silence is much less likely to be taken as agreement by the courts. The OP has already said that their manager approved these expenses. I am not saying that it is impossible that a court could decide otherwise. It is not impossible that the court will decide that the OP is a space alien. But I will suggest that the nature of the expenses, the "why" the expenses were incurred are maybe of more importance legally then whether or not a formal agreement exists. If the employer tells the employee to take actions which incurs reasonable expenses, arguably the "agreement" is pretty much a done deal at that point. If instead the employee is a rouge elephant incurring expenses on their own say so, then agreement is a very strong argument.