Is this swelling or water retention after tummy tuck?

Thank you for your question.  Photos would be helpful.  It's possible that you have a seroma (fluid pocket) that developed after your surgery and never resolved.  Most patients have swelling that resolves over 3-6 months.  Prolonged "squishy" skin may indicate a seroma that might require further surgery.  Best to follow up with your surgeon.   Good luck.  

Thanks for posting. This can be caused by a number of issues including chronic fluid collection (seroma) or incomplete or failed muscle tightening (plication). In person examination or possibly imaging study is needed to assess your condition. Make sure you are seeing an American Board of Plastic Surgey certified surgeon.