That really does not make sense. Were you still employed by the company in 2018 when you received the code M1?
Code M & L are almost the same - it means that money was taken from the retirement plan to pay the loan. Code M means that the reason was that you left employment with the company, and code L means that you defaulted on the loan but were still employed.
Are you sure that the code L is not a corrected 1099-R and the code M was issued in error? You would not be paying the same loan twice. Call the plan administrator for an explanation.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
