@bravestface Pending should indicate that the policy will run the next time the machine checks in. You can't force the policy execution on the server side, but you can make the Mac check in by running the following command in Terminal: 

sudo jamf policy

Thanks. Yes that is the last resort. There are a number of machines to address and many have been managed for years. So there might be more going on with these.

Are they running any policies? Maybe these machines have a policy that is running for a long time. Software Update policies had this issue not long ago where they would essentially never finish and block other policies from running.

I second this. Look at the jamf log on the Mac and see if it's hanging. I've run into this issue out of the blue earlier this year and haven't turned on software update collection since and am not turning it back on until I don't see any more Jamf Nation posts with the issue. I am absolutely not going to run into that problem again. 

Ive seen it before if your upgrading a application and its removing a old Version, The policy might stay in a pending state due to a script running on the machine whcih is waiting for a application to finish uninstalling (requires a reboot). so the policy never completes and reports back as sucessfull.

In this case, there is a removal script that fires before paying it down. I'll look into that angle.

Thank you!