Understand the dog's behavior. In a dog's world, it is instinctual to greet another dog by coming nose-to-nose with them. This allows them to sniff each other's faces and become acquainted with the other dog's scent. Of course, your nose is a bit higher to reach so it is only natural that your dog will jump up to get closer to your face when greeting you. This can be quite annoying and unnecessary, but fortunately, the habit can be broken.
Make sure other family members and visitors understand this command, as well. It is crucial that your dog understand that all family and visitors are above his rank in the pack. Otherwise, he will lash out and try to assert himself on everyone. While using the Off command may not be appreciated by most visitors, but it is more important that a dog has a good greeting manner with all people. A little effort on everyone's side makes your dog disciplined and docile.
When your puppy reaches adolescence, he may be unable to control his impulses and start to test limits (just like a human child). Adolescent jumping up can turn into “nose boinking” which can lead to broken glasses or even a bloody nose. Jumping up often combines with mouthing behavior where the pup bites and grabs your hands, clothing or even your derriere in a grabbing game of tag.
You shouldn’t stop this type of jumping. You need to diagnose your dog's issue and remedy that. If your dog is just stressed being in a new situation, you should calmly get them off of you, offer them a treat to calm them down, and have them sit politely beside you until their stress level has subsided (or take them somewhere else so that they can calm down if it is taking a while for them to calm down.) But most of all, please do not just ignore this behavior change.
When a dog jumps on a human of its own free will, it is not "greeting" the human, it is asserting its dominance over the human; it is the dog communicating that it is alpha and/or wishes to own/control the human. A subordinate would never dream of running over and jumping on the alpha dog of the pack. Space is respect and lower members of the pack respect the higher members. If your dog jumps on humans, it does not respect them. Note: when a young puppy jumps on humans it is sometimes its attempt to reach one's face. Puppies need to be taught not to jump up on humans as this behavior will manifest into other meanings as the puppy grows up into an adult dog.